SystemRestarter for VB.NET - by Elektro

' ***********************************************************************
' Author   : Elektro
' Modified : 02-15-2014
' ***********************************************************************
' <copyright file="SystemRestarter.vb" company="Elektro Studios">
'     Copyright (c) Elektro Studios. All rights reserved.
' </copyright>
' ***********************************************************************

#Region " Usage Examples "

'Sub Test()

'    ' Restart the current computer in 30 seconds and wait for applications to close.
'    ' Specify that the restart operation is planned because a consecuence of an installation.
'    Dim Success =
'    SystemRestarter.Restart(Nothing, 30, "System is gonna be restarted quickly, save all your data...!",
'                            SystemRestarter.Enums.InitiateShutdown_Force.Wait,
'                            SystemRestarter.Enums.ShutdownReason.MajorOperatingSystem Or
'                            SystemRestarter.Enums.ShutdownReason.MinorInstallation,
'                            SystemRestarter.Enums.ShutdownPlanning.Planned)

'    Console.WriteLine(String.Format("Restart operation initiated successfully?: {0}", CStr(Success)))

'    ' Abort the current operation.
'    If Success Then
'        Dim IsAborted = SystemRestarter.Abort()
'        Console.WriteLine(String.Format("Restart operation aborted   successfully?: {0}", CStr(IsAborted)))
'    Else
'        Console.WriteLine("There is any restart operation to abort.")
'    End If
'    Console.ReadKey()

'    ' Shutdown the current computer instantlly and force applications to close.
'    ' ( When timeout is '0' the operation can't be aborted )
'    SystemRestarter.Shutdown(Nothing, 0, Nothing, SystemRestarter.Enums.InitiateShutdown_Force.ForceSelf)

'    ' LogOffs the current user.
'    SystemRestarter.LogOff(SystemRestarter.Enums.ExitwindowsEx_Force.Wait)

'End Sub

#End Region

#Region " Imports "

Imports System.ComponentModel
Imports System.Runtime.InteropServices

#End Region

#Region " SystemRestarter "

''' <summary>
''' Performs different Shutdown system's operations on a local or remote machine.
''' </summary>
Public Class SystemRestarter

#Region " P/Invoke "

#Region " Methods "

    ''' <summary>
    ''' WinAPI methods used by the Main Class.
    ''' </summary>
    Private Class NativeMethods

        ''' <summary>
        ''' Logs off the interactive user, shuts down the system, or shuts down and restarts the system.
        ''' It sends the 'WM_QUERYENDSESSION' message to all applications to determine if they can be terminated.
        ''' </summary>
        ''' <param name="uFlags">
        ''' Indicates the shutdown type.
        ''' </param>
        ''' <param name="dwReason">
        ''' Indicates the reason for initiating the shutdown.
        ''' </param>
        ''' <returns>
        ''' If the function succeeds, the return value is 'True'.
        ''' The function executes asynchronously so a 'True' return value indicates that the shutdown has been initiated.
        ''' It does not indicate whether the shutdown will succeed.
        ''' It is possible that the system, the user, or another application will abort the shutdown.
        ''' If the function fails, the return value is 'False'.
        ''' </returns>
        <DllImport("user32.dll", SetLastError:=True)>
        Friend Shared Function ExitWindowsEx(
               ByVal uFlags As Enums.ExitwindowsEx_Flags,
               ByVal dwReason As Enums.ShutdownReason
        ) As <MarshalAs(UnmanagedType.Bool)> Boolean
        End Function

        ''' <summary>
        ''' Initiates a shutdown and restart of the specified computer,
        ''' and restarts any applications that have been registered for restart.
        ''' </summary>
        ''' <param name="lpMachineName">
        ''' The name of the computer to be shut down.
        ''' If the value of this parameter is 'NULL', the local computer is shut down.
        ''' This parameter can be an addres, for example: '127.0.0.1'
        ''' </param>
        ''' <param name="lpMessage">
        ''' The message to be displayed in the interactive shutdown dialog box.
        ''' </param>
        ''' <param name="dwGracePeriod">
        ''' The number of seconds to wait before shutting down the computer.
        ''' If the value of this parameter is zero, the computer is shut down immediately.
        ''' This value is limited to 'MAX_SHUTDOWN_TIMEOUT'.
        ''' If the value of this parameter is greater than zero, and the 'dwShutdownFlags' parameter
        ''' specifies the flag 'GRACE_OVERRIDE', the function fails and returns the error code 'ERROR_BAD_ARGUMENTS'.
        ''' </param>
        ''' <param name="dwShutdownFlags">
        ''' Specifies options for the shutdown.
        ''' </param>
        ''' <param name="dwReason">
        ''' The reason for initiating the shutdown.
        ''' If this parameter is zero,
        ''' the default is an undefined shutdown that is logged as "No title for this reason could be found".
        ''' By default, it is also an 'unplanned' shutdown.
        ''' </param>
        ''' <returns>UInt32.</returns>
        <DllImport("advapi32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)>
        Friend Shared Function InitiateShutdown(
               ByVal lpMachineName As String,
               ByVal lpMessage As String,
               ByVal dwGracePeriod As UInteger,
               ByVal dwShutdownFlags As Enums.InitiateShutdown_Flags,
               ByVal dwReason As Enums.ShutdownReason
        ) As UInteger
        End Function

        ''' <summary>
        ''' Aborts a system shutdown that has been initiated.
        ''' </summary>
        ''' <param name="lpMachineName">
        ''' The network name of the computer where the shutdown is to be stopped.
        ''' If this parameter is 'NULL' or an empty string, the function aborts the shutdown on the local computer.
        ''' </param>
        ''' <returns><c>True</c> if the function succeeds, <c>False</c> otherwise.</returns>
        <DllImport("advapi32.dll", SetLastError:=True, CharSet:=CharSet.Unicode)>
        Friend Shared Function AbortSystemShutdown(
               Optional lpMachineName As String = "127.0.0.1"
        ) As <MarshalAs(UnmanagedType.Bool)> Boolean
        End Function

        ''' <summary>
        ''' Opens the access token associated with a process.
        ''' </summary>
        ''' <param name="ProcessHandle">
        ''' A handle to the process whose access token is opened.
        ''' The process must have the 'PROCESS_QUERY_INFORMATION' access permission.
        ''' </param>
        ''' <param name="DesiredAccess">
        ''' Specifies an access mask that specifies the requested types of access to the access token.
        ''' These requested access types are compared with the discretionary access control list (DACL)
        ''' of the token to determine which accesses are granted or denied.
        ''' </param>
        ''' <param name="TokenHandle">
        ''' A pointer to a handle that identifies the newly opened access token when the function returns.
        ''' </param>
        ''' <returns>System.Int32.</returns>
        <DllImport("advapi32.dll")>
        Friend Shared Function OpenProcessToken(
               ByVal ProcessHandle As IntPtr,
               ByVal DesiredAccess As Enums.AccessRights,
               ByRef TokenHandle As IntPtr
        ) As Integer
        End Function

        ''' <summary>
        ''' Enables or disables privileges in the specified access token.
        ''' Enabling or disabling privileges in an access token requires 'TOKEN_ADJUST_PRIVILEGES' access.
        ''' </summary>
        ''' <param name="TokenHandle">
        ''' A handle to the access token that contains the privileges to be modified.
        ''' The handle must have 'TOKEN_ADJUST_PRIVILEGES' access to the token.
        ''' If the 'PreviousState' parameter is not NULL, the handle must also have 'TOKEN_QUERY' access.
        ''' </param>
        ''' <param name="DisableAllPrivileges">
        ''' Specifies whether the function disables all of the token's privileges.
        ''' If this value is 'TRUE', the function disables all privileges and ignores the 'NewState' parameter.
        ''' If it is 'FALSE', the function modifies privileges based on the information pointed to by the NewState parameter.
        ''' </param>
        ''' <param name="NewState">
        ''' A pointer to a 'TOKEN_PRIVILEGES' structure that specifies an array of privileges and their attributes.
        ''' If the 'DisableAllPrivileges' parameter is 'FALSE',
        ''' the 'AdjustTokenPrivileges' function enables, disables, or removes these privileges for the token.
        ''' </param>
        ''' <param name="BufferLength">
        ''' Specifies the size, in bytes, of the buffer pointed to by the 'PreviousState' parameter.
        ''' This parameter can be zero if the PreviousState parameter is 'NULL'.
        ''' </param>
        ''' <param name="PreviousState">
        ''' A pointer to a buffer that the function fills with a 'TOKEN_PRIVILEGES' structure
        ''' that contains the previous state of any privileges that the function modifies.
        ''' That is, if a privilege has been modified by this function,
        ''' the privilege and its previous state are contained in the 'TOKEN_PRIVILEGES' structure
        ''' referenced by 'PreviousState'.
        ''' If the 'PrivilegeCount' member of 'TOKEN_PRIVILEGES' is zero,
        ''' then no privileges have been changed by this function.
        ''' This parameter can be 'NULL'.</param>
        ''' <param name="ReturnLength">
        ''' A pointer to a variable that receives the required size, in bytes,
        ''' of the buffer pointed to by the 'PreviousState' parameter.
        ''' This parameter can be 'NULL' if 'PreviousState' is 'NULL'.
        ''' </param>
        ''' <returns>
        ''' If the function succeeds, the return value is nonzero, otherwise, zero.
        ''' To determine whether the function adjusted all of the specified privileges, call 'GetLastError'.</returns>
        <DllImport("advapi32.dll", SetLastError:=True)>
        Friend Shared Function AdjustTokenPrivileges(
               ByVal TokenHandle As IntPtr,
               <MarshalAs(UnmanagedType.Bool)> ByVal DisableAllPrivileges As Boolean,
               ByRef NewState As Structures.TOKEN_PRIVILEGES,
               ByVal BufferLength As UInt32,
               ByVal PreviousState As IntPtr,
               ByVal ReturnLength As IntPtr
        ) As <MarshalAs(UnmanagedType.Bool)> Boolean
        End Function

        ''' <summary>
        ''' Retrieves the locally unique identifier (LUID) used on a specified system,
        ''' to locally represent the specified privilege name.
        ''' </summary>
        ''' <param name="lpSystemName">
        ''' A pointer to a null-terminated string that specifies the name of the system
        ''' on which the privilege name is retrieved.
        ''' If a null string is specified, the function attempts to find the privilege name on the local system
        ''' </param>
        ''' <param name="lpName">
        ''' A pointer to a null-terminated string that specifies the name of the privilege,
        ''' as defined in the Winnt.h header file.
        ''' For example, this parameter could specify the constant, 'SE_SECURITY_NAME',
        ''' or its corresponding string, "SeSecurityPrivilege".
        ''' </param>
        ''' <param name="lpLuid">
        ''' A pointer to a variable that receives the LUID by which the privilege is known on
        ''' the system specified by the lpSystemName parameter.
        ''' </param>
        ''' <returns>System.Int32.</returns>
        <DllImport("advapi32.dll", CharSet:=CharSet.Unicode)>
        Friend Shared Function LookupPrivilegeValue(
               ByVal lpSystemName As String,
               ByVal lpName As String,
               ByRef lpLuid As Structures.LUID
        ) As Integer
        End Function

    End Class

#End Region

#Region " Read-Only Properties (Privileges) "

    ''' <summary>
    ''' Privileges determine the type of system operations that a user account can perform.
    ''' An administrator assigns privileges to user and group accounts.
    ''' Each user's privileges include those granted to the user and to the groups to which the user belongs.
    ''' </summary>
    Private Class Privileges

        ''' <summary>
        ''' Privilege required to shut down a system using a network request.
        ''' User Right: Force shutdown from a remote system.
        ''' </summary>
        ''' For more Info see:
        ''' http://msdn.microsoft.com/en-us/library/windows/desktop/bb530716%28v=vs.85%29.aspx
        Public Shared ReadOnly Property SE_SHUTDOWN_NAME As String
            Get
                Return "SeShutdownPrivilege"
            End Get
        End Property

        ''' <summary>
        ''' Privilege required to shut down a local system.
        ''' User Right: Shut down the system.
        ''' </summary>
        ''' For more Info see:
        ''' http://msdn.microsoft.com/en-us/library/windows/desktop/bb530716%28v=vs.85%29.aspx
        Public Shared ReadOnly Property SE_REMOTE_SHUTDOWN_NAME As String
            Get
                Return "SeRemoteShutdownPrivilege"
            End Get
        End Property

    End Class

#End Region

#Region " Enumerations "

    ''' <summary>
    ''' Enumerations used by the Main Class.
    ''' </summary>
    Public Class Enums

        ''' <summary>
        ''' Indicates the shutdown type.
        ''' </summary>
        <Description("Enum used in the 'uFlags' parameter of 'ExitWindowsEx' Function.")>
        <Flags>
        Public Enum ExitwindowsEx_Flags As UInteger

            '******'
            ' NOTE '
            '******'
            ' This Enumeration is partially defined.

            ''' <summary>
            ''' Shuts down all processes running in the logon session of the current process.
            ''' Then it logs the user off.
            ''' This flag can be used only by processes running in an interactive user's logon session.
            ''' </summary>
            LogOff = &H0UI

        End Enum

        ''' <summary>
        ''' Indicates the forcing type.
        ''' </summary>
        <Description("Enum used in combination with the 'uFlags' parameter of 'ExitWindowsEx' Function.")>
        Public Enum ExitwindowsEx_Force As UInteger

            ''' <summary>
            ''' Don't force the system to close the applications.
            ''' This is the default parameter.
            ''' </summary>
            Wait = &H0UI

            ''' <summary>
            ''' This flag has no effect if terminal services is enabled.
            ''' Otherwise, the system does not send the 'WM_QUERYENDSESSIO'N message.
            ''' This can cause applications to lose data.
            ''' Therefore, you should only use this flag in an emergency.
            ''' </summary>
            Force = &H4UI

            ''' <summary>
            ''' Forces processes to terminate if they do not respond to the 'WM_QUERYENDSESSION',
            ''' or 'WM_ENDSESSION' message within the timeout interval.
            ''' </summary>
            ForceIfHung = &H10UI

        End Enum

        ''' <summary>
        ''' Indicates the shutdown type.
        ''' </summary>
        <Description("Enum used in the 'dwShutdownFlags' parameter of 'InitiateShutdown' Function.")>
        <Flags>
        Public Enum InitiateShutdown_Flags As UInteger

            ''' <summary>
            ''' Overrides the grace period so that the computer is shut down immediately.
            ''' </summary>
            GraceOverride = &H20UI

            ''' <summary>
            ''' Only for Windows 8/8.1
            ''' Prepares the system for a faster startup by combining
            ''' the 'HybridShutDown' flag with the 'ShutDown' flag.
            ''' 'InitiateShutdown' always initiate a full system shutdown if the 'HybridShutdown' flag is not set.
            ''' </summary>
            HybridShutdown = &H200UI

            ''' <summary>
            ''' The computer installs any updates before starting the shutdown.
            ''' </summary>
            InstallUpdates = &H40UI

            ''' <summary>
            ''' The computer is shut down but is not powered down or restarted.
            ''' </summary>
            Shutdown = &H10UI

            ''' <summary>
            ''' The computer is shut down and powered down.
            ''' </summary>
            PowerOff = &H8UI

            ''' <summary>
            ''' The computer is shut down and restarted.
            ''' </summary>
            Restart = &H4UI

            ''' <summary>
            ''' The system is restarted using the 'ExitWindowsEx' function with the 'RESTARTAPPS' flag.
            ''' This restarts any applications that have been registered for restart
            ''' using the 'RegisterApplicationRestart' function.
            ''' </summary>
            RestartApps = &H80UI

        End Enum

        ''' <summary>
        ''' Indicates the forced shutdown type.
        ''' </summary>
        <Description("Enum used in combination with the 'uFlags' parameter of 'InitiateShutdown' Function.")>
        Public Enum InitiateShutdown_Force As UInteger

            ''' <summary>
            ''' Don't force the system to close the applications.
            ''' This is the default parameter.
            ''' </summary>
            Wait = &H0UI

            ''' <summary>
            ''' All sessions are forcefully logged off.
            ''' If this flag is not set and users other than the current user are logged on to the computer
            ''' specified by the 'lpMachineName' parameter.
            ''' </summary>
            ForceOthers = &H1UI

            ''' <summary>
            ''' Specifies that the originating session is logged off forcefully.
            ''' If this flag is not set, the originating session is shut down interactively,
            ''' so a shutdown is not guaranteed even if the function returns successfully.
            ''' </summary>
            ForceSelf = &H2UI

        End Enum

        ''' <summary>
        ''' Indicates the shutdown reason codes.
        ''' You can specify any minor reason in combination with any major reason, but some combinations do not make sense.
        ''' </summary>
        ''' For more info see here:
        ''' http://msdn.microsoft.com/en-us/library/windows/desktop/aa376885%28v=vs.85%29.aspx
        <Description("Enum used in the 'dwReason' parameter of 'ExitWindowsEx' Function.")>
        <Flags()>
        Public Enum ShutdownReason As UInteger

            ''' <summary>
            ''' Application issue.
            ''' </summary>
            MajorApplication = &H40000

            ''' <summary>
            ''' Hardware issue.
            ''' </summary>
            MajorHardware = &H10000

            ''' <summary>
            ''' The 'InitiateSystemShutdown' function was used instead of 'InitiateSystemShutdownEx'.
            ''' </summary>
            MajorLegacyApi = &H70000

            ''' <summary>
            ''' Operating system issue.
            ''' </summary>
            MajorOperatingSystem = &H20000

            ''' <summary>
            ''' Other issue.
            ''' </summary>
            MajorOther = &H0

            ''' <summary>
            ''' Power failure.
            ''' </summary>
            MajorPower = &H60000

            ''' <summary>
            ''' Software issue.
            ''' </summary>
            MajorSoftware = &H30000

            ''' <summary>
            ''' System failure..
            ''' </summary>
            MajorSystem = &H50000

            ''' <summary>
            ''' Blue screen crash event.
            ''' </summary>
            MinorBlueScreen = &HF

            ''' <summary>
            ''' Unplugged.
            ''' </summary>
            MinorCordUnplugged = &HB

            ''' <summary>
            ''' Disk.
            ''' </summary>
            MinorDisk = &H7

            ''' <summary>
            ''' Environment.
            ''' </summary>
            MinorEnvironment = &HC

            ''' <summary>
            ''' Driver.
            ''' </summary>
            MinorHardwareDriver = &HD

            ''' <summary>
            ''' Hot fix.
            ''' </summary>
            MinorHotfix = &H11

            ''' <summary>
            ''' Hot fix uninstallation.
            ''' </summary>
            MinorHotfixUninstall = &H17

            ''' <summary>
            ''' Unresponsive.
            ''' </summary>
            MinorHung = &H5

            ''' <summary>
            ''' Installation.
            ''' </summary>
            MinorInstallation = &H2

            ''' <summary>
            ''' Maintenance.
            ''' </summary>
            MinorMaintenance = &H1

            ''' <summary>
            ''' MMC issue.
            ''' </summary>
            MinorMMC = &H19

            ''' <summary>
            ''' Network connectivity.
            ''' </summary>
            MinorNetworkConnectivity = &H14

            ''' <summary>
            ''' Network card.
            ''' </summary>
            MinorNetworkCard = &H9

            ''' <summary>
            ''' Other issue.
            ''' </summary>
            MinorOther = &H0

            ''' <summary>
            ''' Other driver event.
            ''' </summary>
            MinorOtherDriver = &HE

            ''' <summary>
            ''' Power supply.
            ''' </summary>
            MinorPowerSupply = &HA

            ''' <summary>
            ''' Processor.
            ''' </summary>
            MinorProcessor = &H8

            ''' <summary>
            ''' Reconfigure.
            ''' </summary>
            MinorReconfig = &H4

            ''' <summary>
            ''' Security issue.
            ''' </summary>
            MinorSecurity = &H13

            ''' <summary>
            ''' Security patch.
            ''' </summary>
            MinorSecurityFix = &H12

            ''' <summary>
            ''' Security patch uninstallation.
            ''' </summary>
            MinorSecurityFixUninstall = &H18

            ''' <summary>
            ''' Service pack.
            ''' </summary>
            MinorServicePack = &H10

            ''' <summary>
            ''' Service pack uninstallation.
            ''' </summary>
            MinorServicePackUninstall = &H16

            ''' <summary>
            ''' Terminal Services.
            ''' </summary>
            MinorTermSrv = &H20

            ''' <summary>
            ''' Unstable.
            ''' </summary>
            MinorUnstable = &H6

            ''' <summary>
            ''' Upgrade.
            ''' </summary>
            MinorUpgrade = &H3

            ''' <summary>
            ''' WMI issue.
            ''' </summary>
            MinorWMI = &H15

        End Enum

        ''' <summary>
        ''' Indicates the shutdown reason planning.
        ''' </summary>
        ''' For more info see here:
        ''' http://msdn.microsoft.com/en-us/library/windows/desktop/aa376885%28v=vs.85%29.aspx
        <Description("Enum used in combination with the 'dwReason' parameter of 'ExitWindowsEx' and 'InitiateShutdown' Functions.")>
        Public Enum ShutdownPlanning As UInteger

            ''' <summary>
            ''' The shutdown was unplanned.
            ''' This is the default parameter.
            ''' </summary>
            Unplanned = &H0UI

            ''' <summary>
            ''' The reason code is defined by the user.
            ''' For more information, see Defining a Custom Reason Code.
            ''' If this flag is not present, the reason code is defined by the system.
            ''' </summary>
            UserDefined = &H40000000UI

            ''' <summary>
            ''' The shutdown was planned.
            ''' The system generates a System State Data (SSD) file.
            ''' This file contains system state information such as the processes, threads, memory usage, and configuration.
            ''' If this flag is not present, the shutdown was unplanned.
            ''' </summary>
            Planned = &H80000000UI

        End Enum

        ''' <summary>
        ''' The attributes of a privilege.
        ''' </summary>
        <Description("Enum used in the 'Privileges' parameter of 'TOKEN_PRIVILEGES' structure.")>
        <Flags>
        Public Enum TOKEN_PRIVILEGES_FLAGS As UInteger

            ''' <summary>
            ''' The privilege is enabled by default.
            ''' </summary>
            SE_PRIVILEGE_ENABLED_BY_DEFAULT = &H1UI

            ''' <summary>
            ''' The privilege is enabled.
            ''' </summary>
            SE_PRIVILEGE_ENABLED = &H2UI

            ''' <summary>
            ''' Used to remove a privilege.
            ''' </summary>
            SE_PRIVILEGE_REMOVED = &H4UI

            ''' <summary>
            ''' The privilege was used to gain access to an object or service.
            ''' This flag is used to identify the relevant privileges
            ''' in a set passed by a client application that may contain unnecessary privileges
            ''' </summary>
            SE_PRIVILEGE_USED_FOR_ACCESS = &H80000000UI

        End Enum

        ''' <summary>
        ''' An application cannot change the access control list of an object unless the application has the rights to do so.
        ''' These rights are controlled by a security descriptor in the access token for the object.
        ''' </summary>
        ''' For more info see here:
        ''' http://msdn.microsoft.com/en-us/library/windows/desktop/aa374905%28v=vs.85%29.aspx
        <Description("Enum used in the 'DesiredAccess' parameter of 'OpenProcessToken' Function.")>
        <Flags>
        Public Enum AccessRights As UInteger

            '******'
            ' NOTE '
            '******'
            ' This Enumeration is partially defined.

            ''' <summary>
            ''' Required to enable or disable the privileges in an access token
            ''' </summary>
            TOKEN_ADJUST_PRIVILEGES = &H32UI

            ''' <summary>
            ''' Required to query an access token
            ''' </summary>
            TOKEN_QUERY = &H8UI

        End Enum

    End Class

#End Region

#Region " Structures "

    ''' <summary>
    ''' Structures used by the Main Class.
    ''' </summary>
    Private Class Structures

        ''' <summary>
        ''' An 'LUID' is a 64-bit value guaranteed to be unique only on the system on which it was generated.
        ''' The uniqueness of a locally unique identifier (LUID) is guaranteed only until the system is restarted.
        ''' </summary>
        Friend Structure LUID

            ''' <summary>
            ''' The Low-order bits.
            ''' </summary>
            Public LowPart As Integer

            ''' <summary>
            ''' The High-order bits.
            ''' </summary>
            Public HighPart As Integer

        End Structure

        ''' <summary>
        ''' Represents a locally unique identifier (LUID) and its attributes.
        ''' </summary>
        Friend Structure LUID_AND_ATTRIBUTES

            ''' <summary>
            ''' Specifies an 'LUID' value.
            ''' </summary>
            Public pLuid As LUID

            ''' <summary>
            ''' Specifies attributes of the 'LUID'.
            ''' This value contains up to 32 one-bit flags.
            ''' Its meaning is dependent on the definition and use of the 'LUID'.
            ''' </summary>
            Public Attributes As Enums.TOKEN_PRIVILEGES_FLAGS

        End Structure

        ''' <summary>
        ''' Contains information about a set of privileges for an access token.
        ''' </summary>
        Friend Structure TOKEN_PRIVILEGES

            ''' <summary>
            ''' This must be set to the number of entries in the Privileges array
            ''' </summary>
            Public PrivilegeCount As Integer

            ''' <summary>
            ''' Specifies an array of 'LUID_AND_ATTRIBUTES' structures.
            ''' Each structure contains the 'LUID' and attributes of a privilege.
            ''' To get the name of the privilege associated with a 'LUID', call the 'LookupPrivilegeName' function,
            ''' passing the address of the 'LUID' as the value of the 'lpLuid' parameter.
            ''' </summary>
            Public Privileges As LUID_AND_ATTRIBUTES

        End Structure

    End Class

#End Region

#End Region

#Region " Private Methods "

    ''' <summary>
    ''' Gets the necessary shutdown privileges to perform a local shutdown operation.
    ''' </summary>
    ''' <param name="Computer">
    ''' Indicates the computer where to set the privileges.
    ''' If a null string is specified, the function attempts to find the privilege name on the local system
    ''' </param>
    Private Shared Sub GetLocalShutdownPrivileges(ByVal Computer As String)

        Dim hToken As IntPtr
        Dim tkp As Structures.TOKEN_PRIVILEGES

        NativeMethods.OpenProcessToken(Process.GetCurrentProcess.Handle,
                                       Enums.AccessRights.TOKEN_ADJUST_PRIVILEGES Or Enums.AccessRights.TOKEN_QUERY,
                                       hToken)

        With tkp
            .PrivilegeCount = 1
            .Privileges.Attributes = Enums.TOKEN_PRIVILEGES_FLAGS.SE_PRIVILEGE_ENABLED
        End With

        NativeMethods.LookupPrivilegeValue(Computer,
                                           Privileges.SE_SHUTDOWN_NAME,
                                           tkp.Privileges.pLuid)

        NativeMethods.AdjustTokenPrivileges(hToken, False, tkp,
                                            0UI, IntPtr.Zero, IntPtr.Zero)

    End Sub

    ''' <summary>
    ''' Gets the necessary shutdown privileges to perform a remote shutdown operation.
    ''' </summary>
    ''' <param name="Computer">
    ''' Indicates the computer where to set the privileges.
    ''' If a null string is specified, the function attempts to find the privilege name on the local system
    ''' </param>
    Private Shared Sub GetRemoteShutdownPrivileges(ByVal Computer As String)

        Dim hToken As IntPtr
        Dim tkp As Structures.TOKEN_PRIVILEGES

        NativeMethods.OpenProcessToken(Process.GetCurrentProcess.Handle,
                                       Enums.AccessRights.TOKEN_ADJUST_PRIVILEGES Or Enums.AccessRights.TOKEN_QUERY,
                                       hToken)

        With tkp
            .PrivilegeCount = 1
            .Privileges.Attributes = Enums.TOKEN_PRIVILEGES_FLAGS.SE_PRIVILEGE_ENABLED
        End With

        NativeMethods.LookupPrivilegeValue(Computer,
                                           Privileges.SE_REMOTE_SHUTDOWN_NAME,
                                           tkp.Privileges.pLuid)

        NativeMethods.AdjustTokenPrivileges(hToken, False, tkp,
                                            0UI, IntPtr.Zero, IntPtr.Zero)

    End Sub

#End Region

#Region " Public Methods "

    ''' <summary>
    ''' Aborts a system shutdown operation that has been initiated (unless a LogOff).
    ''' </summary>
    ''' <param name="Computer">
    ''' The network name of the computer where the shutdown is to be stopped.
    ''' If this parameter is 'NULL' or an empty string, the function aborts the shutdown on the local computer.
    ''' </param>
    ''' <returns><c>True</c> if the function succeeds, <c>False</c> otherwise.</returns>
    Public Shared Function Abort(Optional ByVal Computer As String = Nothing) As Boolean

        Return NativeMethods.AbortSystemShutdown(Computer)

    End Function

    ''' <summary>
    ''' Shuts down all processes running in the logon session and then logs off the interactive user.
    ''' </summary>
    ''' <param name="Force">
    ''' Indicates whether to force the logoff.
    ''' </param>
    ''' <param name="Reason">
    ''' Indicates the reason for initiating the shutdown.
    ''' </param>
    ''' <returns>
    ''' If the function succeeds, the return value is 'True'.
    ''' The function executes asynchronously so a 'True' return value indicates that the shutdown has been initiated.
    ''' It does not indicate whether the shutdown will succeed.
    ''' It is possible that the system, the user, or another application will abort the shutdown.
    ''' If the function fails, the return value is 'False'.
    ''' </returns>
    Public Shared Function LogOff(Optional ByVal Force As Enums.ExitwindowsEx_Force =
                                                          Enums.ExitwindowsEx_Force.Wait,
                                  Optional ByVal Reason As Enums.ShutdownReason =
                                                           Enums.ShutdownReason.MajorOther) As Boolean

        GetLocalShutdownPrivileges(Nothing)
        GetRemoteShutdownPrivileges(Nothing)

        Return NativeMethods.ExitWindowsEx(Enums.ExitwindowsEx_Flags.LogOff Or Force, Reason)

    End Function

    ''' <summary>
    ''' Shutdowns the specified computer and begins powered down.
    ''' </summary>
    ''' <param name="Computer">
    ''' The name of the computer to poweroff.
    ''' If the value of this parameter is 'NULL', the local computer is shut down.
    ''' This parameter can be an addres, for example: '127.0.0.1'
    ''' </param>
    ''' <param name="Message">
    ''' The message to be displayed in the interactive poweroff dialog box.
    ''' </param>
    ''' <param name="Timeout">
    ''' The number of seconds to wait before shutting down the computer.
    ''' If the value of this parameter is zero, the computer is poweroff immediately.
    ''' This value is limited to 'MAX_SHUTDOWN_TIMEOUT'.
    ''' If the value of this parameter is greater than zero, and the 'dwShutdownFlags' parameter
    ''' specifies the flag 'GRACE_OVERRIDE', the function fails and returns the error code 'ERROR_BAD_ARGUMENTS'.
    ''' </param>
    ''' <param name="Force">
    ''' Indicates whether to force the PowerOff.
    ''' </param>
    ''' <param name="Reason">
    ''' The reason for initiating the poweroff.
    ''' If this parameter is zero,
    ''' the default is an undefined poweroff that is logged as "No title for this reason could be found".
    ''' By default, it is also an 'unplanned' poweroff.
    ''' </param>
    ''' <param name="Planning">
    ''' Indicates whether it's a planned or unplanned PowerOff operation.
    ''' </param>
    ''' <returns>
    ''' <c>true</c> if the poweroff operation is initiated correctlly, <c>false</c> otherwise.
    ''' </returns>
    Public Shared Function PowerOff(Optional ByVal Computer As String = Nothing,
                                    Optional ByVal Timeout As Integer = 0,
                                    Optional ByVal Message As String = Nothing,
                                    Optional ByVal Force As Enums.InitiateShutdown_Force =
                                                            Enums.InitiateShutdown_Force.Wait,
                                    Optional ByVal Reason As Enums.ShutdownReason =
                                                             Enums.ShutdownReason.MajorOther,
                                    Optional ByVal Planning As Enums.ShutdownPlanning =
                                                               Enums.ShutdownPlanning.Unplanned) As Boolean

        GetLocalShutdownPrivileges(Computer)
        GetRemoteShutdownPrivileges(Computer)

        Select Case Timeout

            Case Is = 0
                Return Not Convert.ToBoolean(
                    NativeMethods.InitiateShutdown(Computer, Message, Timeout,
                                                   Enums.InitiateShutdown_Flags.PowerOff Or
                                                   Enums.InitiateShutdown_Flags.GraceOverride Or Force,
                                                   Reason Or Planning))

            Case Else
                Return Not Convert.ToBoolean(
                    NativeMethods.InitiateShutdown(Computer, Message, Timeout,
                                                   Enums.InitiateShutdown_Flags.PowerOff Or Force,
                                                   Reason Or Planning))

        End Select

    End Function

    ''' <summary>
    ''' Restarts the specified computer.
    ''' </summary>
    ''' <param name="Computer">
    ''' The name of the computer to restart.
    ''' If the value of this parameter is 'NULL', the local computer is shut down.
    ''' This parameter can be an addres, for example: '127.0.0.1'
    ''' </param>
    ''' <param name="Message">
    ''' The message to be displayed in the interactive restart dialog box.
    ''' </param>
    ''' <param name="Timeout">
    ''' The number of seconds to wait before restarting the computer.
    ''' If the value of this parameter is zero, the computer is restarted immediately.
    ''' This value is limited to 'MAX_SHUTDOWN_TIMEOUT'.
    ''' If the value of this parameter is greater than zero, and the 'dwShutdownFlags' parameter
    ''' specifies the flag 'GRACE_OVERRIDE', the function fails and returns the error code 'ERROR_BAD_ARGUMENTS'.
    ''' </param>
    ''' <param name="Force">
    ''' Indicates whether to force the restart.
    ''' </param>
    ''' <param name="Reason">
    ''' The reason for initiating the restart.
    ''' If this parameter is zero,
    ''' the default is an undefined restart that is logged as "No title for this reason could be found".
    ''' By default, it is also an 'unplanned' restart.
    ''' </param>
    ''' <param name="Planning">
    ''' Indicates whether it's a planned or unplanned restart operation.
    ''' </param>
    ''' <returns>
    ''' <c>true</c> if the restart operation is initiated correctlly, <c>false</c> otherwise.
    ''' </returns>
    Public Shared Function Restart(Optional ByVal Computer As String = Nothing,
                                   Optional ByVal Timeout As Integer = 0,
                                   Optional ByVal Message As String = Nothing,
                                   Optional ByVal Force As Enums.InitiateShutdown_Force =
                                                           Enums.InitiateShutdown_Force.Wait,
                                   Optional ByVal Reason As Enums.ShutdownReason =
                                                             Enums.ShutdownReason.MajorOther,
                                   Optional ByVal Planning As Enums.ShutdownPlanning =
                                                              Enums.ShutdownPlanning.Unplanned) As Boolean

        GetLocalShutdownPrivileges(Computer)
        GetRemoteShutdownPrivileges(Computer)

        Select Case Timeout

            Case Is = 0
                Return Not Convert.ToBoolean(
                    NativeMethods.InitiateShutdown(Computer, Message, Timeout,
                                                   Enums.InitiateShutdown_Flags.Restart Or
                                                   Enums.InitiateShutdown_Flags.GraceOverride Or Force,
                                                   Reason Or Planning))

            Case Else
                Return Not Convert.ToBoolean(
                    NativeMethods.InitiateShutdown(Computer, Message, Timeout,
                                                   Enums.InitiateShutdown_Flags.Restart Or Force,
                                                   Reason Or Planning))

        End Select

    End Function

    ''' <summary>
    ''' Restarts the specified computer,
    ''' also restarts any applications that have been registered for restart
    ''' using the 'RegisterApplicationRestart' function.
    ''' </summary>
    ''' <param name="Computer">
    ''' The name of the computer to restart.
    ''' If the value of this parameter is 'NULL', the local computer is shut down.
    ''' This parameter can be an addres, for example: '127.0.0.1'
    ''' </param>
    ''' <param name="Message">
    ''' The message to be displayed in the interactive restart dialog box.
    ''' </param>
    ''' <param name="Timeout">
    ''' The number of seconds to wait before restarting the computer.
    ''' If the value of this parameter is zero, the computer is restarted immediately.
    ''' This value is limited to 'MAX_SHUTDOWN_TIMEOUT'.
    ''' If the value of this parameter is greater than zero, and the 'dwShutdownFlags' parameter
    ''' specifies the flag 'GRACE_OVERRIDE', the function fails and returns the error code 'ERROR_BAD_ARGUMENTS'.
    ''' </param>
    ''' <param name="Force">
    ''' Indicates whether to force the restart.
    ''' </param>
    ''' <param name="Reason">
    ''' The reason for initiating the restart.
    ''' If this parameter is zero,
    ''' the default is an undefined restart that is logged as "No title for this reason could be found".
    ''' By default, it is also an 'unplanned' restart.
    ''' </param>
    ''' <param name="Planning">
    ''' Indicates whether it's a planned or unplanned restart operation.
    ''' </param>
    ''' <returns>
    ''' <c>true</c> if the restart operation is initiated correctlly, <c>false</c> otherwise.
    ''' </returns>
    Public Shared Function RestartApps(Optional ByVal Computer As String = Nothing,
                                       Optional ByVal Timeout As Integer = 0,
                                       Optional ByVal Message As String = Nothing,
                                       Optional ByVal Force As Enums.InitiateShutdown_Force =
                                                               Enums.InitiateShutdown_Force.Wait,
                                       Optional ByVal Reason As Enums.ShutdownReason =
                                                                Enums.ShutdownReason.MajorOther,
                                       Optional ByVal Planning As Enums.ShutdownPlanning =
                                                                  Enums.ShutdownPlanning.Unplanned) As Boolean

        GetLocalShutdownPrivileges(Computer)
        GetRemoteShutdownPrivileges(Computer)

        Select Case Timeout

            Case Is = 0
                Return Not Convert.ToBoolean(
                    NativeMethods.InitiateShutdown(Computer, Message, Timeout,
                                                   Enums.InitiateShutdown_Flags.RestartApps Or
                                                   Enums.InitiateShutdown_Flags.GraceOverride Or Force,
                                                   Reason Or Planning))

            Case Else
                Return Not Convert.ToBoolean(
                    NativeMethods.InitiateShutdown(Computer, Message, Timeout,
                                                   Enums.InitiateShutdown_Flags.RestartApps Or Force,
                                                   Reason Or Planning))

        End Select

    End Function

    ''' <summary>
    ''' Shutdowns the specified computer.
    ''' </summary>
    ''' <param name="Computer">
    ''' The name of the computer to be shut down.
    ''' If the value of this parameter is 'NULL', the local computer is shut down.
    ''' This parameter can be an addres, for example: '127.0.0.1'
    ''' </param>
    ''' <param name="Message">
    ''' The message to be displayed in the interactive shutdown dialog box.
    ''' </param>
    ''' <param name="Timeout">
    ''' The number of seconds to wait before shutting down the computer.
    ''' If the value of this parameter is zero, the computer is shut down immediately.
    ''' This value is limited to 'MAX_SHUTDOWN_TIMEOUT'.
    ''' If the value of this parameter is greater than zero, and the 'dwShutdownFlags' parameter
    ''' specifies the flag 'GRACE_OVERRIDE', the function fails and returns the error code 'ERROR_BAD_ARGUMENTS'.
    ''' </param>
    ''' <param name="Force">
    ''' Indicates whether to force the shutdown.
    ''' </param>
    ''' <param name="Reason">
    ''' The reason for initiating the shutdown.
    ''' If this parameter is zero,
    ''' the default is an undefined shutdown that is logged as "No title for this reason could be found".
    ''' By default, it is also an 'unplanned' shutdown.
    ''' </param>
    ''' <param name="Planning">
    ''' Indicates whether it's a planned or unplanned shutdoen operation.
    ''' </param>
    ''' <returns>
    ''' <c>true</c> if the shutdown operation is initiated correctlly, <c>false</c> otherwise.
    ''' </returns>
    Public Shared Function Shutdown(Optional ByVal Computer As String = Nothing,
                                    Optional ByVal Timeout As Integer = 0,
                                    Optional ByVal Message As String = Nothing,
                                    Optional ByVal Force As Enums.InitiateShutdown_Force =
                                                            Enums.InitiateShutdown_Force.Wait,
                                    Optional ByVal Reason As Enums.ShutdownReason =
                                                             Enums.ShutdownReason.MajorOther,
                                    Optional ByVal Planning As Enums.ShutdownPlanning =
                                                               Enums.ShutdownPlanning.Unplanned) As Boolean

        GetLocalShutdownPrivileges(Computer)
        GetRemoteShutdownPrivileges(Computer)

        Select Case Timeout

            Case Is = 0
                Return Not Convert.ToBoolean(
                    NativeMethods.InitiateShutdown(Computer, Message, Timeout,
                                                   Enums.InitiateShutdown_Flags.Shutdown Or
                                                   Enums.InitiateShutdown_Flags.GraceOverride Or Force,
                                                   Reason Or Planning))

            Case Else
                Return Not Convert.ToBoolean(
                    NativeMethods.InitiateShutdown(Computer, Message, Timeout,
                                                   Enums.InitiateShutdown_Flags.Shutdown Or Force,
                                                   Reason Or Planning))

        End Select

    End Function

    ''' <summary>
    ''' Use this function only for Windows 8/8.1
    ''' Shutdowns the specified computer and prepares the system for a faster startup.
    ''' </summary>
    ''' <param name="Computer">
    ''' The name of the computer to be shut down.
    ''' If the value of this parameter is 'NULL', the local computer is shut down.
    ''' This parameter can be an addres, for example: '127.0.0.1'
    ''' </param>
    ''' <param name="Message">
    ''' The message to be displayed in the interactive shutdown dialog box.
    ''' </param>
    ''' <param name="Timeout">
    ''' The number of seconds to wait before shutting down the computer.
    ''' If the value of this parameter is zero, the computer is shut down immediately.
    ''' This value is limited to 'MAX_SHUTDOWN_TIMEOUT'.
    ''' If the value of this parameter is greater than zero, and the 'dwShutdownFlags' parameter
    ''' specifies the flag 'GRACE_OVERRIDE', the function fails and returns the error code 'ERROR_BAD_ARGUMENTS'.
    ''' </param>
    ''' <param name="Force">
    ''' Indicates whether to force the shutdown.
    ''' </param>
    ''' <param name="Reason">
    ''' The reason for initiating the shutdown.
    ''' If this parameter is zero,
    ''' the default is an undefined shutdown that is logged as "No title for this reason could be found".
    ''' By default, it is also an 'unplanned' shutdown.
    ''' </param>
    ''' <param name="Planning">
    ''' Indicates whether it's a planned or unplanned shutdoen operation.
    ''' </param>
    ''' <returns>
    ''' <c>true</c> if the shutdown operation is initiated correctlly, <c>false</c> otherwise.
    ''' </returns>
    Public Shared Function HybridShutdown(Optional ByVal Computer As String = Nothing,
                                          Optional ByVal Timeout As Integer = 0,
                                          Optional ByVal Message As String = Nothing,
                                          Optional ByVal Force As Enums.InitiateShutdown_Force =
                                                                  Enums.InitiateShutdown_Force.Wait,
                                          Optional ByVal Reason As Enums.ShutdownReason =
                                                                   Enums.ShutdownReason.MajorOther,
                                          Optional ByVal Planning As Enums.ShutdownPlanning =
                                                                     Enums.ShutdownPlanning.Unplanned) As Boolean

        GetLocalShutdownPrivileges(Computer)
        GetRemoteShutdownPrivileges(Computer)

        Select Case Timeout

            Case Is = 0
                Return Not Convert.ToBoolean(
                    NativeMethods.InitiateShutdown(Computer, Message, Timeout,
                                                   Enums.InitiateShutdown_Flags.Shutdown Or
                                                   Enums.InitiateShutdown_Flags.HybridShutdown Or
                                                   Enums.InitiateShutdown_Flags.GraceOverride Or Force,
                                                   Reason Or Planning))

            Case Else
                Return Not Convert.ToBoolean(
                    NativeMethods.InitiateShutdown(Computer, Message, Timeout,
                                                   Enums.InitiateShutdown_Flags.Shutdown Or
                                                   Enums.InitiateShutdown_Flags.HybridShutdown Or Force,
                                                   Reason Or Planning))

        End Select

    End Function

#End Region

End Class

#End Region