Counter Strike Source Crashing Bug

I have had cs source for a while now, but it has never worked completely. I have searched the internet for hours and havent found a solution (plaese dont reply saying to reinstall it). If anyone has a solution please reply

Pc Specs:

6gb ram
Windows 7
x64 bit system
AMD RADEON HD 6450 1 gb graphics card
Intel(R) Core(TM) i5-2400 CPU @ 3.10GHz (4 CPUs), ~3.1GHz

Hope this helps any other people with problems too