CS 1.6 Downlod v42 

I was watching for quality CS 1.6 Download and found great blog with direct downlaod link. 

To play that game you need :

Minimal : 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