Half-Life 2 DirectX Problem

[FERW48]

When I run Half-Life 2 with:
DirectX 9
-It crashes when background animation is loaded
-If it does not crash when background animation is loaded it crashes during a level loading process
-The consequence of a crash is that "No video input" appears at my monitor and the only option is to reset the PC
DirectX 8
-It crashes when background animation is loaded
-If it does not crash when background animation is loaded it crashes during a level loading process
-The consequence of a crash is that some DirectX error appears and the game does not respond but I can call the task manager and close it from there.
DirectX 7
-Seems to load well with all backgrounds
-The levels also load without crashes
-In game white boxes with a cross in them appear on light sources
-The game crashes while "ingame loading" (when you change level) is then when some windows error appear, and when I try to open the task manager it gives me a task manager error (Yep, a task manager error)

The graphic card is GeForce 6200. (Not very new I know)
I got the latest drivers.
I got the latest DirectX redist.

So, any thoughts what could it be and how to fix it. Thanks in advance.

 

[AciD]

Have you tried Verifying GCF Cache Files?

 

[FERW48]

Well I did a bit of research and it seems that white squares with DirectX 7 it's pretty normal event. Another important thing is that the AVG antivirus may cause problems and the only way to get rid of them is to uninstall the AVG. I did so and in effect problems are muchmore less frequent. So if anyone have similar problem, know that it may be cause of AVG.