Left 4 Dead 2

Minimum
CPU: Intel Pentium 4 3 GHz
RAM: 1 GB of RAM (2 GB for Vista and 7)
VGA: NVIDIA GeForce 6600 128 MB or ATi Radeon X800 128 MB
DX: DirectX 9.0c
OS: Windows Vista, XP, 2000
HDD: 13 GB of free hard disk space
Sound: DirectX 9.0c compatible sound card

Recommended
CPU: Intel Core 2 Duo E4600
RAM: 1 GB of RAM (2 GB for Vista and 7)
VGA: NVIDIA GeForce 7600 GS 128 MB or ATi Radeon X1600 128 MB
DX: DirectX 9.0c
OS: Windows Vista, XP, 2000
HDD: 13 GB of free hard disk space
Sound: DirectX 9.0c compatible sound card

Download Link

Google Driver = Download Lift 4 Dead 2
MediaFire = Full Download