This is quite an unusual thing thats happening to me. I play quite a few valve games online like Left 4 Dead (2) and Team Fortress 2 but i have never had this problem before. What happens is when ever i try to use Counter Strike Source with the internet, including a offline server (Just me and 11 bots in it without a connection) it causes my internet connection to basicly die. What happens is i loose connection and it doesn't appear in my available connections dialog. I have had internet problems before but it has never just completly disconected. Then as soon as I exit Counter-Strike my connection eventually comes back to me. This evern happens to me when playing with bots but i am able to play with them but cant connect to online games. When this happens i can't use my internet at all. The loss of connection also happens to my brother on another computer. I have a BT Home Hub, i think it was the first type to come out so below version 2.0. I just know what to do so i need some help. Many thanks. Edit: I felt like trying Left For Dead 2 again and seeing if that still works and it seems the same problem has occured in which i can't connect to a server (after 10 tries) and the internet just...dies. And as soon as I shut down the game it fixes itself.