AGP cannot go to 4x or 8x

Ive been recently expereincing the problem most people seem to be having allot lately, repeating sound loops and crashing while in games. Im not to good with hardware so ive been depending on forums and other resources to help me out. I came acrosse a site that seemed to have helped allot of people with the same problem. The problem can sometimes be caused by the northbridge, or specifically the CPU to AGP Controller. This made sence to me because in my long efforts to correct this problem I even replaced my motherboard with an identical one thinking maybe it was flawed, the problem presisted. To give you an Idea of what i actully changed here were the instructions i followed.

Right click-mouse over My Computer
Properties
Hardware(Tab)
Device Manager(button)
Click [+] next to System devices
right-mouse on CPU to AGP Controller (or whatever your controller is called, mine was SiS AGP)
Update Driver(button)

Select Install from a list or specific location (Advanced)
Next(button)
Select Don't search. I will choose the driver to install.
Next(button)
Select PCI standard PCI-to-PCI bridge
Next(button)
Finish(button)
Reboot.

Problem is now I expereince a different kind of freeze up. After a little more poking around I realized this is because i disabled the agp controller so it cant even go to 4x non the less 8x. Ive been looking into a bios update but I heard its kind of risky if not done correctly you could end up with a expensive paper weight.

Any help resolving this would be appreciated

System Specs
intel p4 2.8 HT enabled
asus p4p800 e deluxe MB
1024mb memory
ati x800 xt all in wonder

let me know if you need any more information, thanks.

Reinstall your motherboard drivers,which includes the AGP driver.Then reinstall the video card drivers after rebooting.

In most recent Bios you can set the AGP between disable / 1 / 4 / 8.

Is the card even working in AGP mode? Go check smartgart and see what it says.

Seems like by removing the driver and replacing it by PCI - PCI bridge - you forced your card into PCI mode, so no wonder the freezes.

As peterdiva said - try to reinstall mobo drivers, reboot, install graphics card drivers and reboot.