Set dtmInstallDate = CreateObject("WbemScripting.SWbemDateTime")
strComputer = "."
Set objWMIService = GetObject( "winmgmts:\\" & strComputer & "\root\cimv2")
Set objOS = objWMIService.ExecQuery( "Select * from Win32_OperatingSystem")
For Each strOS in objOS
dtmInstallDate.Value = strOS.InstallDate
Wscript.Echo dtmInstallDate.GetVarDate
Next