I bought my emachines t6420 computer about 3 years ago and last summer my motherboard had fried which resulted in my computer not being able to start. I replaced the power supply and motherboard. I replace it to a an "Elite Group" brand mother board and it worked fine and I got my computer running again. 3 months later the computer started to shut off itself and later i noticed that whenever i watch videos after 3 minutes the computer shuts off itself. Now its just if i use any kind of media/games it will just shut off. What can i do to fix this problem? I have been reading around that it could be a problem with the video card or heating up or it could be program that i need to install. I really hope its just a problem with a program or software. What can i do to fix this problem?