New GPU, PC running very slow

Hello. I just bought a Radeon HD 6870 from visiontek and after i uninstalled my old drivers and installed the new card i reset my pc and the performance of my pc slowed down so much i can barely start IE just to type this. i have seen other posts about the problem might be caused by my psu but so far none of them have helped.

These are my specs tell me if you need some more info

Motherboard ASUS M4A77TD
CPU AMD Phenom II X4 955
2 X 2GB Ram
Xion High Performance 700 Watt PSU
+12V1 25A

Also I'm not sure if this may be the problem but the PSU has a 6+2 pin that splits into a 6+2 pin I'm using both of those to power the card.

I'd try a friends reliable power supply and see if that helps.

You didn't say that you downloaded the most current driver from AMD. If you haven't done that already I'd make that my first priority.

Yes i already got the most updated drivers.

Anyone else got any other suggestions?

Be certain you have no infestations. There are two out there in various forms... starts with a slow down of the computer, then an infestation on screen as Windows XP Security 2012, or Windows 7 Security 2012, or what appears to be two installs of windows.

Sorry raybay I'm not sure of what you are talking about exactly.

lol i you not the only one who confused about raybay's post, ignore that. you need 2 separate 6+2 pin plugs to power the card, so if your only running one it won't be powering it properly

Well i feel like a complete ***** i was using the old power cord for my 300watt PSU which was not giving me enough power i put in the new cord and everything is working fine now. Sorry to waste everyones time.

good to hear