Originally Posted by MyCardSuXXors
I have to reinstall losing lots of important data in the process.
I don't suppose it occured to you to back up your data before the upgrade?
Anyway, power supply, video card driver and BIOS information would be helpful. Far as power supply, what brand/total wattage is it? What is its +12v rating? Since the card is apparently not working in another system, it's probably the cause and you should see if you can return it to the place you bought it from.