hl2 episode 1 crashes

[TaMs]

So my hl2 episode 1 worked fine untill i got to the place where you can get crowbar. After that there's loading place where it crashed like 4 times when i tried. Then yesterday i tried again and i got through the loading
but now everything on the background crashes but hl2 works.(almost) : D i can see it through my keyboard screen (g15) Everything just shuts down.

Then it will go like that or some other annoying things happen like there's no enemies or alyx has black eye and only head etc.

This doesn't happen in episode 2 or tf2 or portal. so i could assume that my episode 1 is broken, but can it be just half broken? just weird. Or maybe my computer is just breaking down. I'm getting alot of those hm... can't remember what they're called but those things what'll come if you overclock your video card too much. And it's not even clocked. So my trustly radeon 9800 could be dying what's causing this all, but dunno.

Any idea to fix it? just reinstall or sumthing?

ps. the error what i got when it was still crashing was something like
"Engine error
internal driver error in Idirect3ddevice9:resent()"

 

[Samutz]

Right click on HL2 in steam and click Properties. On the Local Files tab click the Verify integrity of game cache button.
Then do it again for EP1.

Also, update your video card drivers, directx, etc.

You can also delete the cache files and reinstall them through Steam.

Although the last time I had a problem that looked like that, the video components on the motherboard (laptop) were physically damaged. And the graphic corruption was occurring in every game.