For just under the cost of a 6850 you could get this:
1. AMD Athlon II X4 640 Propus 3.0GHz Socket AM3 95W Quad-Core Desktop Processor ADX640WFGMBOX
2. ASUS M4A785-M AM3/AM2+/AM2 AMD 785G HDMI Micro ATX AMD Motherboard
Combo Price: $157.98
The board would allow you to reuse your current RAM.
My question is why are you running a 2-bit version of Win7?