I have a Windows 7 computer here, which is freezing between 2 times a day and 1 time every second day. I see no problem, no special drivers, no special Apps are open, no encryption or something like that. Apps usually open then are Firefox, Thunderbird, Eclipse and maybe Office.

Computer is just freezing. No Reboot, no shutdown, no bluescreen and no error. User has to hardreset it. Eventlog shows me an kernel error saying it has been unexpected rebooted due to an fatal error, but no statement about what kind of error happended.

Anyone an idea what it can be? Chkdisk should be ok (currently, I run it a second time).