problem with new graphics card. URGENT!!please

[Sai Teja]

I bought new graphics card 650 ti boost. I uninstalled on board graphics drivers and cahnged BIOS settings INIT dispalay as PEG. Then installed graphic card along with 6pin connector from PSU. But booting stuck at
loading operating system...
and i m even unable to enter in bios settings. I even tried after updating Bios.Nothings worked
config:-
Amd 955BE
Gigabyte GA-880Gm-USB3 v3.1
4GB ram
500W cooler master (It has 6 pin connector)
Zotac 650ti boost

 

[Sai Teja]

1) Even unable to enter in to safe mode. Problem is keyboard is not working with GPU installed.
2) I have shifted from win 7 to 8.0 for checking purpose. no use.

Seems all the possible doors have closed for me.