Help, I can't play anything !!!

Everytime I join a game, after a minute or so, I get kicked to the lbby with the error "Caould not connect to the host server" or something like that, (im paraphrasing of course). Before it kicks me, every one starts to run on the spot like really bad lag.
I have tried reinstalling, I have also change my firewall settings and my anti-virus settings. I don't know what is wrong.
Can someone help me please ?