I have a late 2008 model unibody mbp, and yesterday at a gig i noticed a slight audio drop out then my audio interface crashed traktor. I unplugged it and the computer froze so i restarted it and from that point it was running so incredibly slow really taking a long time to log in and load anything. Eventully not letting me log into that account but lets me use other accounts ive made fine. I did put in my old hard drive and it worked fine, so i put the current hd back in and did an archive install. And im still getting really really slow performace i cant open system preferences or anything it will open after a while but then i get that wheel etc. What I want to do is several things 1. Perform clean my mac on the user even tho im logged in in another incase its anything in the cache (how do I do this?) 2. Find out exactly whats caused it I cant take the risk of it happening again when im at a gig 3. This happened about a year ago so it cant be the new hard drive it must be some software could it be SMC fan control? I really hope I can get this sorted P.S Ive repaired permissions also. EDIT how do I do a virus scan on another account?