Hl2.exe Error

Today playing in some server, my Gmod crashed, I tried to run it back, it loads for some seconds and then a windows message shoWs up saying windows closed Hl2.exe.
I tried reinstalling Gmod, restarting the PC, even trying to find the fix through youtube or differents forums, but nothing worked.
I have windows XP, 2Gb ram and Nvidia 6600, enough for run Gmod, it had crashed a few times before but I might run it back. Every other game works, except HL2 EP2 or EP1, but HL2 works perfectly.

Can anyone help me, please?

Thanks.

Update drivers?

Already done.

Don’t Worry About It, The Last Update Is Not Compatible With Some Gamemodes. Try it Out Play Garrysmod In Sandbox Compared To DarkRp You Will Crash In Rp And Not In Sandbox

I Wonder Why People Have Started Talking Like This?
On topic: check the task manager to see if it already has a Gmod or HL2 proccess running.

Doesn’t it gives an error when you try to launch the game that you already have Gmod/HL2 running?