The method is quite simple if u know about ur computer
1:click start now click "control panel"
2:there u see "windows firewall" click on it
3:ok in windows firewall click in "exceptions"
4:click "add port" there
5:now u see 2 things 1 is "name" n other is "port number" n "TCP" n "UDP" box there
6:u write "Counter-Strike 2D" in the name
7:n "36963" in port number
8:finally put dot in UDP N CLICK OK DONE......