http://www.half-life2.org.uk/check.php
Half-Life 2 : System Test 
Results 
  Processor: Your processor is fine.  
  Graphics : You should be able to play in 1024x768 depending on your card, consider upgrading if you have an older chipset such as GeForce 3 Ti  
  System Memory: You have enough RAM  
  Operating System: You will be able to play on Win XP.  
  Architecture: No Problems  
Please don't forget that you need a DirectX 6 compatible card to be able to play Half-Life 2, a DirectX 9 card will however give much better graphics.
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