XP only boots in safe mode - gpu problem

Hi there,
my spec is as follows:
mobo: asus a8n-sli deluxe
cpu: amd x2 4200
ram: 2gb ddr (1x 1gb, 2x 512)
gpus: 2 of nvidia 7800gt
hard drive: 160gb maxtor
runing windows xp 32 bit sp3

i recently replaced my chipset fan as the standard one had become noisey and worn.
while replacing the first of my gpu's i caught one of the voltage regulators on the newly installed chiopset cooler (as it is taller than standard) and ripped it off the card! so now the card is damaged.

anyway after getting frustrated at this, i decided to try and set my computer up to run just with one gpu.
the problem i have is that powering the pc up with just the one gpu that still works does not even allow the bios to load, i do not even get a POST check beep. there is nothing, no beep, no display.
but strangely whn i put the broken gpu into the other PCIe slot and turn the pc on, it boots up into bios fine but then gets stuck on the windows xp loading screen a split second after it has come up, i do not even see the animated bar scrolling across.
the pc will load up safe mode ok, but will not load windows properly at all.

i have tried changing the connector on the mobo round from the dual gpu side to the single gpu side, but this has made no difference. i have also tried with and without having power feeding to the broken gpu, it will still load up safe mode either way.
i have also tried having the gpu in both PCIe slots but it made no difference.

what i want to know is how to make it run just with one gpu, until i can afford to buy a replacement card.

your help is greatly appreciated.
Tim

 

yeah, i have tried that but when i try to run just the one good card the computer freezes on the windows xp screen.
do i also need to go into the device manager when in safe mode and disable the second faulty gpu in the other pcie slot. then remove the card and restart the pc?

 

sorry, what i mean is, i have changed it in the bios so that it is set on one graphics card. then when i boot up with just the one good graphics card i do not even get the bios loading let alone the windows xp screen.