gmod dont start

hello,

I have buyed gmod on steam and the following thing happends when i start the game:
i see a picture man standing in the field in the corner of the picture is the text: loading but after a time the games stops and windows says: hl.exe dont work anymore.

any idee how to fix? i use vista

Edit:
I own garrys mod and counter strike source.

Bump

Computer specs? Also 13 hour bump not needed.

O srry for all this specs:

  • vista
  • 2 gb ram
  • dual T2390 1.86(intel pentium)
  • video driver is onboard(mobile intelĀ® 965 Express Chipset family)
    and its a laptop

Edit:
I have found the prob i used the command -dxlevel 81 i must update the dirext x.