#Reset-GPOCache.ps1
#Alan dot Kaplan at VA dot GOV
#3/17/2015

#Deletes local copies of GPO and forces a GPUpdate

[long]$HKLM = 2147483650
$computer = $env:COMPUTERNAME

Add-Type -assemblyname Microsoft.visualBasic
$Computer = [Microsoft.VisualBasic.Interaction]::InputBox("Enter computer name to reset GPO cache", "Name", "$computer")
if ($computer.length -eq 0){exit}

if ((Test-Connection -Count 1 -ComputerName $computer -Quiet) -eq $False) {
Write-Warning "$computer is offline"
Exit
}

Try{
$WMIConnect = "\\"+$computer+"\root\Default:StdRegProv"
$RegProv = [WMIClass]$WMIConnect
}Catch{
    Write-Warning $Error[0].Exception.Message
    Exit
}

$ShellFolders = "SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders"
$AppData = ($RegProv.GetStringValue($HKLM, $ShellFolders, "Common AppData")).svalue
$DeletePath = "\\"+$computer+"\"+$AppData.Replace(":","$")+"\Application Data\Microsoft\Group Policy\History\"
c: 
write "Deleting cache files in $deletePath"
Remove-Item -Path $DeletePath -Recurse  -Force -ErrorAction SilentlyContinue


$startup=[wmiclass]"Win32_ProcessStartup"
#Create a process with process startup configuration to hide the window using [wmiclass] accelerator
$startup.Properties['ShowWindow'].value=$False
$command = "GPUpdate /force"
Try{
    $retval = ([wmiclass]"\\$Computer\ROOT\CIMV2:Win32_Process").create($command,$null,$Startup)
    Write "Ran `"$command`" on $computer"
    exit
}Catch{
    Write-Warning "Failed to run $command on $computer with error:"
    $errmsg = $Error[0].Exception.Message
    [regex]::Matches($errmsg,'Error.*').value
    }