[XP] White blinking cursor

OK I was working on a Dell Dimension 8200. it has a garbled display it boots up fine but you can barely read the screen. so I suggested a new video card. I put in a new agp card and it worked until they restarted it. it would show the dell splash screen and then just sit with a white cursor in the upper left corner. I also tried other agp cards and even a pci card but all give the same result. even the original card still only goes to a certain point. and something garbled blinks. if i try to press F2 to go into bios it says Error 8602 Auxiliary Device Failure.

Try clearing the CMOS in case it got scrambled. There should be a jumper on the motherboard to do that, if there isn't or you can't find it then pulling the motherboard battery out for a few minutes will achieve the same result (unplug the power lead as well).

already did the clear cmos.

FYI I'm not near the machine.

From my reading, it looks like this error is caused by some USB device, most likely mouse, or keyboard.
Disconnect all USB devices, and restart. If error is gone, try to plug them in one-by-one.