Windows 7. I had to add a new Outbound rule to Windows Firewall to "Allow the connection" for %ProgramFiles%\Java\jre6\bin\javaw.exe
To find the javaw.exe that Minecraft uses, first close Minecraft, "Start Task Manager" and look at the Processes tab, then when you start Minecraft you should see a new javaw process pop into the list. Right click on the process in task manager and look at "properties". On the General tab, note the "Location" of the the javaw.exe. That's the one you have to allow to connect through Windows Firewall.
0
To find the javaw.exe that Minecraft uses, first close Minecraft, "Start Task Manager" and look at the Processes tab, then when you start Minecraft you should see a new javaw process pop into the list. Right click on the process in task manager and look at "properties". On the General tab, note the "Location" of the the javaw.exe. That's the one you have to allow to connect through Windows Firewall.