Help! Computer problems

[Awoir]

Last night for like 5 hours my comp was running at like 0.00001 FPS with just windows up. When I'd open the task manager it'd say CPU usage was 100%. Now it's running at the usual 0-10% fluxuation, but after being on for anywhere from 10-60 minutes a box pops up saying [Program error] "lsass.exe has generated errors and will be closed by Windows. You will need to restart the program. An error log has been created [Cancel]. Then after I hit cancel in about 5-10 minutes a box pops up saying theres an error with program at C:\WINNT\system32\lsass.exe and windows will restart in 1 minute. What do I do to fix this? D;\

[Vinen]

That process is highly prone to virus's if I remember... I'd try a virus scan if I were you... the symptoms you have sound very... similar to me.

[Awoir]

It has kinda the symptoms of an old virus that was around when SP2 just came out that would make windows restart. I read that file was really prone to viruses but AVG doesn't find anything the matter with it. Any other free programs people know that I can d/l?

[Mysterio]

http://i73.photobucket.com/albums/i2...echsupport.jpg

[Toralyn]

I've got the same problem >_>

I've run virus scans though, and nothing came up. Ditto for Adaware and Spybot.