Here is another small tip that may help someone out.

To find which ports are open on your windows pc.

Open a command prompt then type

netstat -na

It will list the ports that are open and listening on your pc as well as any that have any that have an ESTABLISHED connection to them. (see the example image below).

All pcs need to have some ports open to communticate on a network. If there is one that you are not sure of, search for the port number on google to get more info.