I changed my motherboard recently to Asrock. Soon after my Windows 2000 installation started crashing (read: Blue screen of death). Even Safe mode with Networking failed to boot.

I isolated the problem to vsdatant.sys, which turned out to be ZoneAlarm file. Uninstalling ZoneAlarm solved the BSD problem. Next I tried to install a new version of ZoneAlarm. While installation it gave me blue screen. So I aborted further attempts to install ZoneAlarm.

Windows XP too faced problems with loading ZoneAlarm. However unlike Windows 2000, XP didn't crash. It appears Windows XP is more robust than Windows 2000 as far as BSD is concerned.