My computer is a couple of years old and I have run it with no issue until recently. Occasionally during a game it would show a crazy flickering array of colors and the speakers would make a humming sound. I instantly thought graphics card. I have been running it hard that day and I thought it had overheated or something. I left my computer off for a few days and then ran it with no issues. A few days later on start up from being off as soon as it got passed the windows boot screen it did the weired colors, but started fine on a reboot and it has every time. This went on for a few days, some times on boot up and sometimes in game. Always random without a connection to the total time running. I can always see the bios screen and the windows splash screen. Tonight I started it and after the windows screen it just a solid blue screen on one monitor and a purplish-blue on the other. This is a long running set up that I haven't tampered with or anything. The motherboard is an Asrock P54TS-R, the Graphics are an Nvidia 280, the CPU is Q9550.
You running Vista? I had an issue with my Vista "melting" where the code would degrade with use. I found that turning off pagefile made it last longer, but it still burned up in a matter of months.
If you don't have Vista, then I would look at your RAM for developing errors. After that, if the RAM is fine, the maybe the mainboard. May be your HDD too. Just start testing till something throws an error.
First things first, if your computer is giving weird video issues, try video first! You're mobo does not have onboard graphics so you will need to get a friend, borrow a card and try it out. You could have easily over done the card one day, degrading it so now it will randomly act up, its not unheard of for parts to go bad over time especially after heavy use. So try that out and get back to us on the status of your comp.
My computer will boot up fine in Safe mode but not in normal. And seeing as how my Motherboard has no on board graphics that would exclude my Graphics card right? Makes it seem more of a software issue.
Update: I uninstalled the drivers and was able to boot up normally but as soon as I installed them the computer went solid colored again after the reboot.