Crysis 2 requirements detailed
 

The upcoming Crysis 2 will apparently work on XP, Vista and Windows 7 OS and minimum specs include a Intel Core 2 Duo 2GHz, AMD's Athlon 64 x2 2GHz or better, 2GB of memory, Nvidia 8800GT 512MB, ATI HD 3850 512MB or better and 9GB of HDD space. It is also noted that you'll need an active internet connection, presumably for activation.

http://fudzilla.com/games/item/21749...ments-detailed