Big HL2 Problem Please Help!! Game Won't Load

[tuneman 23]

Perhaps I am a noob, but I have installed HL2 several times before without issues. Now I am installing onto another pc. When all is installed and Steam updates the game to %100 ready. I start HL2 and steam tells me its preparing to run it. Then nothing happens. I open Task Manger in Xp and I can see HL2.exe running, but the game has not loaded in 3d?!!? Incidently I loaded it on my own pc at the same time and all is fine.

If I try again Steam says "game is currently unavailable. Please try again later. Here are my specs"

p4 3 gig
I gig ram
Xp home
ATI 9600XT 256 ram

Thanks guys, I hope we can sort it cuz I'd love to play the new coop mod with my friend.

 

[tuneman 23]

I thought I would mention that CS Source is running fine on the same machine...please help

 

[Jintor]

How long do you wait for HL2 to start up?

And as a general all-round trouble solver, revalidate your files and try again.