My computer is an HP Pavilion a818n and it has been running fine until one month ago where the computer will randomly restart without warning. I can be on the internet, typing up an essay, or playing a game or so. The screen will turn black and randomly restart with no error display. I reinstalled Windows XP and got rid of every program to see if that would fix it but apparently did not do a thing. Now when i try to reinstall some of my programs I had, it wont complete the installation and just restart in the middle of it. I don't think its a heat problem or a virus problem either. HELP PLEASE! if you need more information on the computer, please request.