How do i take a virus off, when not even Norton detects it?

[Konder]

Last night my computer rebooted without warning or explanation. It came back up with everything normal seeming so I assumed it was one of those bastard windows updates. About an hour later I was using firefox and then it stopped responding to clocks. Outside of firefox, a mouseclick was recognized once per item, but no more. Using alt + ctrl + del results in the icon for the system monitor showing up in the tasktray, but nothing more. I could not interact. I rebooted it in safe mode and used system restore to take it to about 3 days back. (I haven't had any other day work so far and I've tried at least 10 different days.) I thought it had fixed it, and I left the computer running all night with no programs open. In the morning, I went to firefox and after about 10 minutes, everything locked again. Rebooted and tried internet explorer with the same result. I just now removed firefox 3.0 and then installed 3.5, but that didn't change anything. While downloading new nvidia drivers (I suspect that it's a graphical problem) the system locked again and I just now rebooted. I am very frustrated. Neither AVG nor SpyRemover find any viruses or other malware. They're both up to date. Part of what is bothering me is that there are no symptoms of viruses or malware outside of this. In some ways, that would almost be preferable. At the moment though, I am stuck, so please do what you can to help.

[Josh]

Sounds like it crashed and therefore restarted. It could be happening due to many different things. To first rule out malware, download, install, update and then run a system scan with the free MBAM. If it finds anything, remove it and reboot. See if the issues are fixed. If not, it could be hardware or Windows related. Posting your system specs and version of Windows would help...

[torquemasterice]

Might be better to run scans in safe mode. There is an on demand scanner by eset, but i dunno if it's free...