In order for you to play Zombie Panic! Source on Windows with minimal graphics settings, your computer must meet the following requirements
OS *:
Windows® 7 (32/64-bits)/Vista
Processor (CPU):
1.7 GHz Processor or better
Memory (RAM):
2 GB RAM
Graphics Card:
Video Card Shader Model 3.0
DirectX:
Version 9.0c
Network:
Broadband Internet connection
Storage:
8 GB available space
Sound Card:
DirectX 9.0c compatible sound card
In order to play Zombie Panic! Source on Windows with maximum graphics settings, you need a computer with a configuration no worse than the following
OS *:
Windows® 7 (32/64-bits) or above
Processor (CPU):
2.4 GHz Dual Core Processor or better
Memory (RAM):
4 GB RAM
Graphics Card:
nVidia 7600, ATI X1600 or better
DirectX:
Version 9.0c
Network:
Broadband Internet connection
Storage:
8 GB available space
Sound Card:
DirectX 9.0c compatible sound card