: Detailed version history and links can be explored on the official Valve Developer Wiki Installation Tips Half-Life Requirement
If you already own on Steam:
Here is the most reliable method to get CS 1.4 running on a modern PC. Download Counter Strike 1.4
Released in April 2002, version 1.4 was a major milestone that introduced the first version of the system and improved the "jump-landing" penalty to prevent bunny-hopping exploits. It remains a favorite for purists who want to see the game exactly as it was before the massive 1.5 and 1.6 updates. How to Get It Running : Detailed version history and links can be