I have a problem with some Source games...

[Takuanuva]

Okay, so here's the situation:

-Portal and Half Life 2: Episode 2 work fine, even with graphics set to maximum.
-Half Life 2 and Half Life 2: Episode 1 won't even show the main menu: they show the "Valve" clip, loading screen (for 5-15 seconds), and then crash (the game minimizes itself and refuses to work).
-Garry's Mod (without any addons) shows the loading screen just like HL2 and HL2:Ep1, but instead of minimizing itself, the screen goes black, after which I get the information that hl2.exe ceased to work.

I don't think it's problem with my PC, since all of these were working just fine before. I already removed all of these games and all related files and reinstalled them (multiple times), no effect whatsoever.

Any ideas?

 

[FreakSheet]

I don't have an answer for you, but I did have a similar problem with Just Cause 2. I got the game during the sale ($5. F' YEAH.) and like a month later when I tried to play it crashed. I tried again. Crashed. My insane self tried four more times, and it suddenly worked. I have no idea how, but it did.

I would recommend rebooting, or if you have another PC (and a generous internet cap) downloading it there.