Resolved Rebooting After updating graphics card drivers, Gives solid black screen

Im having a issue with one of my older PC's. I just updated my nVIDIA performance program... The only thing i use it for is to moniter the tempratures of my card...My computer locks up and after a while of fiddling with no responce I restart it, I have no POST screens or anything just black, I have an onboard graphics card, so I pulled the card to see if i could role back the driver but i still get a black screen...

How on earth can I role back the drivers or attempt to fix this if i get nothing but black?

I tried new RAM, and another card thats mega old, but i get nothing. my moniter works when i plug it into my laptop. how Can i get my onboard working so i can re_install old drivers?

My setup:

Main board: MSI 915G combo
CPU: Intel P4 prescott VT6410 @ 3.00 GHz
Mem: 2x 1 Gig kingston DDR2
Graphics: MSI Nvdia NX7600GS-T2D256EH 256Mb
Powa: AGI 500W

(http://www.msi.com/index.php?func=proddesc&maincat_no=130&prod_no=820)

 

last known good configuration.. have you tried it?

 

I cant I have no POST or power on self test which is where you could select the option, the bios chip on my board is fried i just got my new replacement mobo and everything works fine...

thanks for the help