Neo, I don't believe he would get any video signal if he plugged his monitor into the new GPU without switching the graphics output in the BIOS first.
Shelf, are you sure you plugged your monitor into the GPU?
OP, show us a picture of your device manager.
In Win 7 Start--> Control Panel--> Hardware and Sound--> Device Manager.
Select display adapters and take a screencap of that.
If the card appears in the device manager, I would highly recommend that instead of using XFX drivers
, you go directly to AMD's website and download the latest driver