Problem running HL2

[deadduck]

I get an error when ever I try and start a game in HL2 it will just exit to desktop altering my screen size settings. I have just recently got the orange box first I played portal which worked fine I am not sure as to why HL2 will not load the first level when portal works fine with the same engine.

 

[deadduck]

been getting this error massage IDirect3Ddevice9:: present() found an old thread on this http://www.halflife2.net/forums/showthread.php?t=72866&page=7 hopefully I can find something that works.

Edit: by lowering to Directx 8 for halflife 2 got first level to load however crashes as soon as I entered another area. then I lowered the tecture models and charactor models and was able to play the game properly.
I have a ati X700 mobility graphics card which meets the 128mb stated on the back of the box (shrug) so I am suprised I had to do this