Dim oComputerSystem : Set oComputerSystem = GetObject("winmgmts://.").InstancesOf("Win32_ComputerSystem")
Dim bMember : bMember = false


For Each oEntry in oComputerSystem
If oEntry.DomainRole = 1 then
WScript.Echo "Computer is Member of a Domain"
bMember = true
Exit For
End if
Next

If (bMember = false) then
WScript.Echo "Computer is not Member of a Domain"
End if