multiple problems with this computer. Whether these are related to hardware problems, or related hardware failures, or problems to do with malware or other software issues is impossible to say at this stage. You haven't given any details of this machine, nor its history.

So any advice has to be generic, and I would start with the processes offered in the discussion below;
http://forums.cnet.com/5208-6142_102-0.html?threadID=358991&tag=forum-w;forums06

Mark