Help, L4D and HL2 crash all the time

[flyingSnow]

They will crash about 2~3 seconds after running. And steam will make a error report.
I tried plenty of ways I've found, but still not work.Such as 'copy DLL', 'run as Admin' ,'run by steam or directly' and a lot.

My computer:
Win 7, Cure2 T6670, GT 320M with newest drivers, and 4G RAM

I can run HL2 with argument '-vr' in steam. But HL2 doesn't work property with Virieo.

I can run them with Perception 'disabled' or closed - of course not in vr mode. 'Oculus', 'Anaglyph' will make it crash, even in 'No Tracking' state.

Thank You!