Have you run the diagnotic CD that came with it? That should repair any small problems. You want to back up any important files on to CD or other hard drive. You many need to invest in some better diagnotic program. I like TechTool Pro but there are other goods ones as well. Of course, if it can't find any problems you may have to take it to the shop. BUT BEFORE YOU DO ANYTHING BACK UP YOUR FILES. This comes from someone that didn't. Ugh! What a mess I was in. Good luck.