I have an upgraded Gateway FX 6800-01e that I bought a few years ago. It has:
Windows 7 Home Premium x64
9 GB of DDR3 RAM
750 GB HDD
Intel Core i7 920 @ 2.67 GHz
ATI Radeon HD 4870
The computer originally came with Vista, but I upgraded it to Windows 7 (clean install). All of my drivers are up to date, I've defragged the hard drive, run disk cleanup, checked for viruses. I haven't gotten around to testing my RAM and hard drive to see if they are all working properly.
I can run games, but most lag terribly (to the point of not being able to be played). I'm mainly trying to play Crysis, Rainbow Six Vegas 1 + 2, Assassin's Creed 1 + 2, the Battle for Middle Earth series, and the Prince of Persia series. Some of these (Prince of Persia), I know weren't programmed for Windows 7, and I've thought about installing Windows XP as a dual boot, but I don't know if I want to do all that work. Compatibility mode also doesn't fix it.
Is there anything I can do to fix it? I don't play games very often, but now I can't really play any at all.