Think i got a fix for this, it was either one of 2 problems
1. i had a program called peerblock to block unwanted people from trying to access my computer, which i just closed,
2. go to advanced settings for your firewall which is located in your control panel>windows firewall>advance settings> and delete the 2 maximum then do this
New Rule
Custom
browser for program then go to your steam folder >steam apps>common>Crysis 2 Game of Year edition>Bin32 and add the crysis2.exe
Then for protocol drop the menu down, select TCP
Then tick all the boxes for networks
Then add a name for it i put Crysis 2 Maximum Edition
Then do the same again but this time for protocol select UDP
then reboot and then try again :)
http://www.youtube.com/watch?v=VjU5VsLg2Cc maybe of more detail if you need it :)