Left 4 Dead

Minimum system requirement:

• Supported OS: Microsoft Windows XP / Vista / Vista64
• Processor: Pentium 4 3.0GHz
• Memory: 1 GB
• Graphics: 128 MB, Shader model 2.0, ATI 9600, NVidia 6600 or better
• Hard Drive: At least 7.5 GB of free space
• Sound Card: DirectX 9.0c compatible sound card

Recommended system requirement:

• Supported OS: Microsoft Windows XP / Vista / Vista64
• Processor: Intel core 2 duo 2.4GHz
• Memory: 1 GB
• Graphics: Shader model 3.0, NVidia 7600, ATI X1600 or better 

Left 4 dead