Okay, the first and simplest thing to try to make sure you get the latest Windows Updates onto your machine...disable the Sophos Firewall Service. Type Service.msc into a run command, scroll down until you find Sophos Firewall and then stop and disable the service.
Now do a Windows Update. Once its finished and rebooted, etc go back in and enable the firewall.
I'm just trying to find out which file you can alter to change settings in the firewall...we dont use it at work but I know most settings can be altered wven after being locked down.
Give the above a try and I'll get back to you as soon as I've figured it out!