Just when I thought I was done with my other E-Machine, my wife's girlfriend gave me another one. This one has a AMD Athalon XP 2400 processor at 2GHZ and a Nvidia 5200 128mb V.C., windows XP-Pro with 2GB of ram. I boot it up and it runs great for about 25 minutes and then it freezes up. I can see the last video section of a movie I was playing and the HDD LED Light stays on. There is no beeping noise of any kind and I had to shut the system down. I waited about an hour and rebooted the thing and placed another movie in the DvD-Rom drive. It to played for about 25 minutes and it locked up again. Now, here's some more info. Turned out that my wife's girlfriend's husband changed out the processor chip and heatsink. I'm kind of wondering if this is the culprit. I recently upgraded my other e-machine from a 1600 to a 2400 chip and a brand new heatsink and fan along with a better power supply and it works to perfection. Do any of you fine folks out there think whether this is a processor problem or a Video card or HDD problem? Any help will be greatly appreciated. Thanks.