Does anyone know of any free tool that I can use to monitor all client computers to see if they have been updated or not by a microsoft software update services (SUS) server?
You can use a program called QFECheck. It's provided from MS and verifies each hotfix. It's very nice. The Network thing, well I don't know about one, but you can try using your login script to report the problems. the program takes only a few seconds to run and con generate a report anywhere.