"HL2.exe Has stopped working" whenever I try to load Garry's Mod.

I have had a problem. When I start Garry’s Mod the loading screen pops up but then I am returned to the Desktop and told that “HL2.exe has stopped working” Any Help please?

I have a Vista computer. I have just installed the vista service pack 2.

My computers specs are:
Processor- Intel Pentium Dual CPU T3400 2.17GHz
RAM-3GB
OS: Vista 32 bit.

I have the Orange Box and all those games work fine. It is just Garry’s Mod.

Also not sure whether relevant but, while following advice from steam forum I have changed settings for the Data Execution Protection, in hope that it would help but it didnt. any help would be appreciated, thanks.

do you have the latest drivers for your video card?

I am not sure, can you please tell me how to update my drivers?

Did it used to work? If so, try redownloading the game (Clearing local content)

Right click Garry’s Mod under “My Games”, click “Properties” then click “Set launch options…” type in “-dxlevel 90” if that doesn’t work try something lower like “-dxlevel 81”, etc.

Hope it helps.

It depends on what graphic card you have. Press Windows key + R and type in dxdiag, then in the new window that comes up, go on the display tab at the top, and see what it says after “Name:”