2.6 Gig Pent 4
Windows XP SP1
1 g ram
Ati Radeon 9800 pro
Asus Motherboard P4S800

I've had my ATI card for a couple years now, I've never been good with computers, and this is the first time I've seriously sat down to try and fix this problem, when my friend first put my computer togethor for me, I couldnt get it to boot up unless I set the graphics card AGP speed to x4, whenever I set it to x8 it either freezes as soon as I boot up, or it freezes when i load up a game. Or it will go into hardware deadlock or something and it switches to the motherboards buiilt in graphics. My friend who is pretty good with computers as far as im concerned took it to his house for a few days to see if he could fix it and couldn't. I think it might have to do something with the voltage between the VGA and the motherboard. I really have no clue tho, please somebody heeeeelp!

What is the power rating on your power supply? The problem could very well be caused by a weak PSU.

Your mobo is an AGPX8 mode 3.0 (0.8volts) and the 9800 Pro is a mode 2.0 (1.5V). But set to AGPX4 then it will take the 1.5V signal.
Here's an article: http://www.planet3dnow.de/artikel/diverses/agp30eng/index.shtml

The long and short is you might damage your mobo if you set it to AGPX8 using a mode 2.0 card and the performance increase is negligable, so leave it at X4.

Thanks for the help guys. I actually got the computer to start in 8x, it didnt seem to make any difference tho, in fact some games that i play ran so choppy I was unable to even play them. Oh well thanks tho!