My computer freezes repeatedly and not at anyspecific time. I have re-installed windows, all my drivers are up-to-date, I bought a new CPU fan since previously the CPU temp was 60C (pretty high), I ran memtest and that gave me NO errors. I've run virus scans and haven't found anything yet. I have also cleaned up my registry, etc. When I run defrag, it would run most of it and then freeze up which doesn't help too much. From the memtest, the memory seems to be working fine, my hard-drive is in good condition. I'm not sure what the problem could be. Has anyone come across this before? Any suggestions on what can be done next?