I guess I'm the one of very few CS:S players here at the moment.
This place is predodimantly 'haunted' by flight-simmers (that's why I'm here really)
I've tried helping you out over at the CS:S forum.
http://forums.steampowered.com/forums/showthread.php?s=&threadid=259835
You said you get Program not responding...
What did you do before the program stopped responding? What OS do you have?
You have got the Microsoft VR engine installed I take it? What version?
You can get the Microsoft VR Engine as part of MS Office or the
larger download of VAC. ( i think you installed the larger one didn't you?)
You're in the right place for a fix anyway- somebody more qualified than I am will stop by soon to help you out I'm sure.