Gigabyte GeForce - Recent Questions, Troubleshooting & Support

Look for your drivers here.

In the nvidia control panel you can overclock you're card. But there isn't much headroom on the card.

I would suggest adding it to the computer possibly as a secondary card if possible. Once the card (if it works) is installed run a benchmark or a game and see if the ps blue screens if not you can be pretty sure the card is ok. If the card does not boot at all and nothing shows up on screen it is badHope this helpsJack

Do you have a question?

http://www.geforce.com/drivers you will need java for this or manually choose your driver

just make sure the drivers are up to date. I know they released a new one for that series about a month ago. the older cards aked up from time to time. I have SLI 9800gtx's and they will do weird stuff sometimes then recover.

It sound like you may have a dodgy motherboard, if you have tried 2 card in the pci-e slot and neither work it's quite possible, If you can try the cards in another machine to eliminate the cards as the fault. the other thing to also test is the PSU but if the system otherwise seems stable then it's not likely this is the issue.

HERE

Probably your graphic card is damaged.
Buy a new graphic card.

I'm not sure of your exact model number because there are a couple of different versions but, I believe yours is GV-N450oc2-GI because of the 2 DVI ports. You freezng is more than likely due to an outdated driver. This is Gigabyte's link for downloads:
http://www.gigabyte.com/products/product-page.aspx?pid=3600&dl=1#driver
If this is your correct model number, I have entered your info so all you have to do is choose your o/s and download. It is recommended that you uninstall prior driver before installing new. If you have any questions, let me know.

If the system is hanging at login then it is probably a windows issue. I would suggest trying to start in safe mode by holding down f8 as you start up your computer. If it works after that then I would suggest reinstalling windows as it will be a driver issue of some sort. You probably do have some sort of windows issue with all of that hardware swapping that you have done so doing this would not be a bad idea at all.