hd 7750 for $64, this one is much faster than old 8800gts..
http://pcpartpicker.com/part/powercolor-video-card-ax77501gbk3h
well, this is an old graphic card..
usually this series have touch the limit of it's age..
7 years is old for an electronic..
so try this..
clean your graphic card golden bridge with contact cleaner or pencil eraser..
then try it again..
this one is the simplest method how to fix an error on your computer..
or, you can do baking method to temporary fix your graphic card..