Counter Strike 1.6

PC System Requirements:

Minimum: 1.7 GHz Processor, 
512MB RAM,
 DirectX® 8.1 level Graphics Card (Requires support for SSE),
 Windows® 7 (32/64-bit)/Vista/XP,
 Mouse, Keyboard, 
Internet Connection

Recommended: Pentium 4 processor (3.0GHz, or better), 
1GB RAM, DirectX® 9 level Graphics Card, 
Windows® 7 (32/64-bit)/Vista/XP,
 Mouse, Keyboard,
 Internet Connection