So I decided to start thinking and I used @Serror instead of @Error to get a better idea of the problem. Apparently Error Code 21 is "Device not ready." Any idea what device it might be speaking of? To answer your question, yes, I tried using the UDF that will shutdown/restart/logoff a computer (local or remote) via WMI and recieved the same error code. I'm begining to think it has something to do with the test workstation's odd set up.