Well, you have a few things wrong with that. One, get the original Crysis. The original Crysis is A LOT better looking than Warhead. Two, Play on Vista to actually use DX10. Three, that's no $600 dollar build. If you had to pay for Vista it would be a whole bunch more.
Also,JoeBro, I would just save up more money. If you want a gaming computer you can't cheap out of the video card first of all. Get about $600 and a 8800GT and you would be okay. $800 for me in the minimum for a gaming PC, but that's just me.
I had the original Crysis. I borrowed it from my cousin though. I deleted it because I finished the game and wasn't a fan of the multiplayer. I'm not a fan of Vista. I gave it a chance and didn't like it. I wouldn't go to Vista, ONLY for DirectX 10.It's not worth it to me. I can run enthusiast setings on Warhead. In my opinion, Warhead is better than the first Crysis. Sorry to anyone who thinks otherwise. But that's just my personal opinion.
Processor:$189.99
GFX: $110.99
RAM: $44.00
Motherboard: $89.99
Case: $75.98
Total: $510.95