"hl2.exe stopped working"

Hello,
I am a former CS:S player from a few years back and just opened a new account with steam. I downloaded the bundle with CS:S and gmod because I’ve always been curious about the gmod program. CS:S has been running smoothly, even though I’m on a laptop (TOSHIBA Satellite A-305, Standard), but when I launch gmod, I’ll get to the screen with the guy holding the traffic cone on the other’s head, see the loading sign in the bottom left, then it will close out and the error “hl2.exe stopped working” comes up. Any suggestions?
Thanks

[editline]08:24PM[/editline]

sorry, found the thread on this