I have XP.
I installed mechwarrior 4, and the internet thing popped up, telling me that mechwarrior was trying to access the internet, I chose Block. I now want to unlblock it, but I don't know how to. ;9
Goto Control Panel and then into Windows firewall and go into the 'Exception' tab. You will see Mechwarrior untickied, tick it and press OK.
Or just like, stop using windows firewall =)