I installed Windows 7 without any problems, and have had it running for a few days with no problems. Then, yesterday, I tried to install MS Office, and halfway done my screen froze. I turned the computer off manually, and restarted, and now, even if I'm not doing anything, it turns itself off just after a little while.
I have run Vista on it before with no problems for over a year, and have done nothing with the hardware.
The computer gets very warm, so I'm thinking it might have to do with overheating, but why??