This is common for on line games when there is an interruption in the network connection. Freezes are also common when the server changes maps. You will usually see Network Connection Problem in the upper right corner after a few seconds in all Half Life based games. When you see that, it's typically the server and not you. You can open the console and type retry and see if that works. If it fails after the 4 auto attempts, more than likely the server has crashed. A good way to test it quickly if that happens to be one of your favorite servers, get the IP address and the IP address of another one or two of your favorites. When you get the "lock up", see if you can open the console and type retry first. If that fails, type connect (then the IP address of a different server without the parenthesis) for example: connect 192.168.4.205 If you can connect immediately to a different server then obviously, the one you play on crashes alot and you might want to think about finding a different one. If you cant connect, you more than likely have some sort of local issue going on. Big things to look for, make sure Windows Firewall is disabled, dont run any anti-virus programs while playing and try to have as few programs running in the background as possible. You especially don't want any file sharing or torrent software running. Hope that helps.