The crash you describe is one I've encountered a couple of times on PCs running Win2000, which in my experience is normally very stable. In my case the crashes were in some way time-related - maybe system resources being used up and not properly released again until a hard reboot. That may be what's happening in your case - probably a glitch arising from the new configuration. If you have different OSs on the two machines, and one can see the other, wholly or in part, that too could be a factor.

Anyway, maybe someone will weigh in with an informed view, and maybe solution, now I've refreshed the thread.