Here are the Crysis 2 System Requirements (Minimum)
CPU: Intel Core 2 Duo 2.0 GHz, AMD Athlon 64 X2 2.0 GHz or better
RAM: 2 GB (Vista requires 3 GB)
VIDEO CARD: NVIDIA GeForce 8800 GT 512 MB of memory or higher; ATI/AMD Radeon HD 3850 512Mb RAM or higher
DEDICATED VIDEO RAM: 512 MB
PIXEL SHADER: 3.0
VERTEX SHADER: 3.0
HARDWARE T&L: Yes
OS: Windows XP, Vista or Windows 7, with the latest Service Pack
FREE DISK SPACE: 9 GB
SOUND CARD: Yes