I have a Compaq Presario R3000 AMD WinXP that was givin to me by my brother in law. Hard drive was shot so I bought a new one and Installed fresh copy of WindowsXP using the compaq disc that was provided. It has been working fine for days untill the other day when I was using it and it randomly turned off. No blue screen or anything. I turned it back on. Windows booted fine. Once I got to the windows log in screen I heard the fan kick on loud and shut down. Tried booting again, Same problem. Came back to it in a few hours, it was fine. Seems to be overheating....I thought this untill I started it up cold one day after sitting for days and it did the same thing, Windows log in, fan kicks on, shuts down. Sometimes after turning it back on it will work fine...I don't get it!