Problem with prebuilt/custom running Crysis

Okay, so I was able to get an HP Pavilion p6610f desktop PC for $285 on clearance. I swapped out the stock 250w PSU with a 500w PSU I already had and put my Nvidia GeForce 210 graphics card in it. I have all the latest Windows updates and the latest Nvidia drivers. It has the following specs...

AMD Athlon II X4 635 Quad-Core processor clocked at 2.9GHz with a 4,000MHz FSB
Nvidia Geforce 210 1GB GDDR2
4GB of PC3-10600 RAM
AMD 785G Chipset

The Windows Index Rating is...
Processor: 7.3
Memory (RAM): 7.3
Graphics: 4.9
Gaming Graphics: 5.8
Primary Hard Disk: 5.9

Now, I can't run Crysis on anything that even RESEMBLES pretty or playable. When I choose optimal settings, it sets everything to high, but once I get in-game, it's choppy as hell. I tried lowering everything to the lowest settings, and that BARELY got it over 30 FPS. Am I missing something? I have a PowerColor Radeon 6850 coming in the mail in the next few days to replace the GeForce 210, but until then I've got no idea what to do. Any help would be appreciated.

-Ben

P.S. I was running it in DX10 mode instead of DX9 if that matters