Windows has stopped gpu due problems

Ok i have been building custom rig from scraps and everything went fine installing drivers etc. I've installed windows 7 professional sp1 and windows as usually detected vga but when i try to install nvidia driver and reboot vtune says "please reinstall/uninstall program". Cant start nvidia control panel and in device manager gpu is disabled due problems i've trying reinstalling but nothing.
Specs:
Pentium 4 3.0 dual core
Mobo 775 dual-vsta last update
Gpu nvidia 520
500w
Ps: yea i know old pc....
Ps2: after mindblow ive set pci express to boot first and disabled agp( i think i spell it correctly) and ive managed to install driver and im stuck at disabled gpu..
 
I think the issue is the port on the motherboard. It is PCI-e, but not PCI-e x16. The card is probably not fully compatible with that old of a port. PCI-e x16 standards are backwards compatible, but I don't think you can run a x16 card in a pre-x16 port.

ASRock shows the PCI-e port runs at x4:
http://www.asrock.com/mb/VIA/775Dual-vsta/index.asp?cat=
 



Here is the supported VGA list:
http://www.asrock.com/mb/VIA/775Dual-VSTA/?cat=VGA

Also make sure the BIOS are up to date as much as possible. Some of those GPU's need a specific BIOS version. BIOS should be in the "Downloads" section on that linked page.
You could probably get one of them on eBay and fairly cheap. Also it mentions the driver package of the time.
 


From what I remember of that period, the 8800GTX was the fastest and the 8800GTS was really good and more affordable. You could also look at the HD2900XT which is faster than the rest of that list, but not better than the 8800GTX/GTS.
 


Not a waste, I have a legacy machine that is older than yours. I find these to be fun for the most part. It helps me appreciate the progress in technology + I can run really old games on it, that wont work on Windows 7. Mine is:

Pentium D 945 (recently upgraded from a P4 3.2 ghz w/HT)
ASUS P5V800-MX
2GB DDR400 RAM
Sapphire 3850 AGP 8x
Windows XP Pro