Ok, this isnt for half life 2, but a mod (http://www.hidden-source.com)
Look at the game first please : )
basically, its kinda annoying, when the game thinks i have DirectX 8.1, but actually i can have nine.
And i wouldnt be to bothered, except, the game is EXTREMELY hard to play, without being able to see the hiden with DirectX 9
Just wondering i there is anyway i could get it to recognize DirectX9