Windows 7: CS:S Problem

Hi, I'm having a problem with CS:S. When I try to join a server it just stops in the server lodaing screen. It doesn't freeze, cus I can cancel the loading. I also can't find any servers, the only way how I "find" servers, is when I try to join a friends game, that's where it stops in the loading screen.
What can I do? Please ask if it's a bit confusing :S

Do you have a valid steam account to go with the game or did you get some no-steam version from the internet?
It seems that you are denied by the servers you are trying to connect, whether having a wrong protocol (which I doubt) or you just have the non-steam version of the game and try to connect to steam-only servers.

I have tryed on my other pc to join servers with the same account, and I was able to join servers ad play normally.

Check if your firewall is blocking the game or not.

Now it works. The problem was the fireawall, but it was because of McAfee, which controlled my firewall. My McAfee was a free trial of the full version, and because the trial time had ended it blocked my Css.

Glad I was able to help. Always check your firewalls first when software connections fail.
Cheers!