sExePath = "\\Yourserver1\patches\WindowsXP-KB927891-v3-x86-ENU.exe"
sSwitches = "/u /q /z"
Set oShell = CreateObject("WScript.Shell")
sRegKey = "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate"
' suppress error in case values does not exist
On Error Resume Next
' check for marker
sRegMarkerValue = "" ' init value
sRegMarkerValue = oShell.RegRead( sRegKey & "\WindowsXP-KB927891-v3-x86-ENU.exe")
On Error Goto 0
' to be sure update is installed only once, test on marker
If sRegMarkerValue <> "yes" Then
oShell.Run Chr(34) & sExePath & Chr(34) & " " & sSwitches, 1, True
' create marker
oShell.RegWrite sRegKey & "\WindowsXP-KB927891-v3-x86-ENU.exe", "yes"
End If