New-Folder

<#
.Synopsis
   For 1 or more computers, for a given folder root, create the folders, and the subfolders in the script here
   If the computers are not in a domain, then you will be prompted for credentials
.Description
   Also see http://technet.microsoft.com/en-us/library/ff730951.aspx
   $session = New-PSSession -ComputerName "jan-pc"
   Enter-PSSession -Session $session
   Get-ACL "C:\sandbox\PowerShell\artefacts\subFolder" | Format-List
   Which returns eg
   Path   : Microsoft.PowerShell.Core\FileSystem::C:\sandbox\PowerShell\artefacts\subFolder
        Owner  : BUILTIN\Administrators
        Group  : Jan-pc\denni_000
        Access : BUILTIN\Administrators Allow  FullControl
                 NT AUTHORITY\SYSTEM Allow  FullControl
                BUILTIN\Users Allow  ReadAndExecute, Synchronize
                NT AUTHORITY\Authenticated Users Allow  Modify, Synchronize
                NT AUTHORITY\Authenticated Users Allow  -536805
        Audit  :
        Sddl   : O:BAG:S-1-5-(snip)OICIID;0x1200a9;;;BU)(A;ID;0x1301bf;;;AU)(A;OICIIOID;SDGXGWGR;;;AU)

.Example
   New-Folder -ComputerName "dennis-pc","Jan-pc","emma-pc" -FolderRoot "\Test3"
#>
function New-Folder
{
    Param (
        [Parameter(Mandatory=$true, Position=0)]
        [string[]]
        $ComputerName,
        [Parameter(Mandatory=$true, Position=1)]
        [string]
        $FolderRoot = "C:\TestFolder1",
        [Parameter(Mandatory=$false, Position=2)]
        [string]
        $UserName = "BUILTIN\users"
    )
    Begin {
          $fileRights = [System.Security.AccessControl.FileSystemRights]"FullControl"
          $InheritanceFlag = [System.Security.AccessControl.InheritanceFlags]::ContainerInherit
          $PropagationFlag = [System.Security.AccessControl.PropagationFlags]::InheritOnly
          $objType =[System.Security.AccessControl.AccessControlType]::Allow
    }
    Process {
        foreach ($computer in $ComputerName) {
          "Processing $computer..."
          Invoke-Command -ComputerName $computer -Credential $cred -ScriptBlock {
                param($FolderRoot1, $UserName1, $fileRights1, $InheritanceFlag1, $PropagationFlag1, $objType1)
                if (!(Test-Path -Path $FolderRoot1)) {
                    "Creating folders in $FolderRoot1..."
                    New-Item -ItemType directory -Path $FolderRoot1
                    New-Item -ItemType directory -Path $FolderRoot1/Backup
                    New-Item -ItemType directory -Path $FolderRoot1/Error
                }

                $objUser = New-Object System.Security.Principal.NTAccount($UserName1)
                $objACE = New-Object System.Security.AccessControl.FileSystemAccessRule ($objUser, $fileRights1, $InheritanceFlag1, $PropagationFlag1, $objType1)
                $objACL = Get-ACL $FolderRoot1
                $objACL.AddAccessRule($objACE)
                Set-ACL $FolderRoot1 $objACL
            } -ArgumentList ($FolderRoot, $UserName, $fileRights, $InheritanceFlag, $PropagationFlag, $objType)
         }
    }
}