No signal after installing new GPU and downloading drivers

[oCrispyyy]

Hello there, I received a GPU that I bought off eBay today and have been struggling to get it working. Prior to installing the new GPU I disabled my onboard graphics and deleted those old drivers, then I downloaded the AMD driver software and then turned off my PC, opened it up and inserted the new GPU into it. I got a signal and booted into Windows with the windows basic drivers, then I used the AMD software to detect my hardware and it successfully did, began to download and install the drivers then halfway through I got a No Signal message popping up on my monitor. I restarted the PC after a while and I get a signal when I turn it on, it gets to the Windows 8 loading screen and then loses signal. Any help?

Specs
AMD Phenom II X2 555
AMD Radeon HD 6570
4 GB of RAM

EDIT - so now I have my AMD drivers installed, but when I boot up into windows 8 I get past the loading screen then i get a black screen with the ability to move my cursor and I see a network icon but nothing else. This is the last thing I need to fix before I can finally get it working, any help?

An issue that has popped up is a windows 8 error code 0xc00000f?

 

[Hellfire13]

get into bios...enable onboard graphhics...reboot the computer...go to windows...uninstall the amd driver...rebbot the system with the gpu now...install a previous driver if it works and see if that helps...else u might have to rma the card...