I have an idea what the probem is, but no solution. Maybe someone else might though. My best guess is that windows is not shutting down correctly. I had a faulty hard drive, that would clunk once, then spin back up. My windows would freeze for about 5 seconds then carry on as normal. If I got a 'delayed write failed' message and rebooted, all my settings such as zonealarm program access etc were lost and I had to reconfigure everytime. If I had to reboot my pc as a result of it locking up, the same thing happened.