Cannot load Gmod; PLEASE HELP!!

I bought Garry’s Mod off of Steam yesterday, and every time I try to load it, hl2.exe crashes.

ALL RELATED INFO IS IN THIS PACKAGE:

Attempted fixes:
-Reinstalling Garry’s Mod
-Restarting Steam
-Re-Booting my computer

NOTE: Every game shown in my Steam “Games” tab has been launched at least once on this computer, and they all run perfectly fine.

Thank you for your time, and in-advance for your solutions.
-wowimaperson

EDIT:
I have not even ATTEMPTED to install any add-ons. Just thought this might be useful information.

Please, somebody?

I REALLY want to play this. =D

go to steam right click g-mod go to properties then advanced launch options put this in there “-window -dxlevel 70 +mat_forcehardwaresync 0”

i just did that and it worked for me just remove the quotes

EDIT:

oh and if you want it to be fullscreen switch “-window with -fullscreen”

And if that doesn’t work, your specs?

T_T

Specs are in the garrysmod.zip/dxdiag.txt

But anyway, I tried those launch options, and it worked!!
So I kept trying to make it better and better, until I figured out that it will run with DirectX 8.1, but not 9 or 9.5, and that I don’t need “+mat_forcehardwaresync 0”.

Btw, BEST TEN BUCKS I EVER SPENT.