Public Sub BeginImpersonation()
    Const LOGON32_PROVIDER_DEFAULT As Integer = 0
    Const LOGON32_LOGON_INTERACTIVE As Integer = 2
    Const SecurityImpersonation As Integer = 2

    Dim win32ErrorNumber As Integer

    _tokenHandle = IntPtr.Zero
    _dupeTokenHandle = IntPtr.Zero

    If Not LogonUser(_username, _domainname, _password, LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT, _tokenHandle) Then
        win32ErrorNumber = System.Runtime.InteropServices.Marshal.GetLastWin32Error()
        Throw New ImpersonationException(win32ErrorNumber, GetErrorMessage(win32ErrorNumber), _username, _domainname)
    End If

    If Not DuplicateToken(_tokenHandle, SecurityImpersonation, _dupeTokenHandle) Then
        win32ErrorNumber = System.Runtime.InteropServices.Marshal.GetLastWin32Error()

        CloseHandle(_tokenHandle)
        Throw New ImpersonationException(win32ErrorNumber, "Unable to duplicate token!", _username, _domainname)
    End If

    Dim newId As New System.Security.Principal.WindowsIdentity(_dupeTokenHandle)
    _impersonatedUser = newId.Impersonate()
    _impersonating = True
End Sub

Enum LOGON32_LOGON
    INTERACTIVE = 2
    NETWORK = 3
    BATCH = 4
    SERVICE = 5
    UNLOCK = 7
    NETWORK_CLEARTEXT = 8
    NEW_CREDENTIALS = 9
End Enum
Enum LOGON32_PROVIDER
    [DEFAULT] = 0
    WINNT35 = 1
    WINNT40 = 2
    WINNT50 = 3
End Enum
Enum SECURITY_LEVEL
    Anonymous = 0
    Identification = 1
    Impersonation = 2
    Delegation = 3
End Enum

Dim myProcessStartInfo As ProcessStartInfo = New ProcessStartInfo

    With myProcessStartInfo

        .FileName = "file path and name"

        .Domain = "domainname"
        .UserName = "username"

        'password needs to be a SerureString
        Using NewPassword As New Security.SecureString
            With NewPassword
                For Each c As Char In "password".ToCharArray
                    .AppendChar(c)
                Next c
                .MakeReadOnly()
            End With
            .Password = NewPassword.Copy
        End Using

        'UseShellExecute must be false for impersonated process
        .UseShellExecute = False

    End With

    Using Process As New System.Diagnostics.Process
        With Process
            .StartInfo = myProcessStartInfo
            .Start()
        End With
    End Using

LogonUser(_username, _domainname, _password, LOGON32_LOGON_NEW_CREDENTIALS, LOGON32_PROVIDER_WINNT50, _tokenHandle)

Declare Auto Function CloseHandle Lib "kernel32.dll" (ByVal handle As IntPtr) As Long
Declare Auto Function RevertToSelf Lib "advapi32.dll" () As Long