OK so the last Steam update was a complete fuckup, but we can fix it till they do it again..
One of the things Steam has changed is the DirectX level of the games for the new HDR download to come.
If you have an older card and you find that the game is more sluggish, with a worse ping and/or bad FPS then try this.
Goto: Play Games
> Right Click on Counter Strike Source
> Goto and Click Properties
> Click Launch OptionsNow what you need to do is to place in the DirectX level of your card.
type
-dxlevel 81if that doesnt work try
-dxlevel 80and if you have a really old card try
-dxlevel 70close that and run CSS.
This has worked for me as under dxlevel 90, which is now the default i was getting 50% less FPS and ping spikes every 30secs.
Now if you have a problem where the game is quiting on you, then its most likely to be a memory error. You can increase your memory by stopping the amount of processes and applications that are launched when you start up our PC. Becareful tho cos you can mess things up, so i wont tell you how to do this,
but i will give you a link to follow.. and if you dont understand it, dont do it, and if you do it dont come running to me if it brakes