(NOTE: These instructions are written for those using the Windows 7 Firewall. However, they should work for any other software-based firewall.)
1. Open Windows Firewall control (in Start Menu run box type "WF.msc")
2. You are going to create 2 new rules: 1 inbound and 1 outbound.
3. On the left side, select Inbound Rules. Then, on the right pane, you will see an option for a New Rule. Click it (see below).
4. In the New Inbound Rule Wizard (which should appear), do the following:
- Choose Program and click Next
- Select This Program Path, and enter the path to javaw.exe on your PC (typically \Program files\x86\java\jre6\bin)
- Choose Allow the Connection, then Tick Private and Public.
It is important to note that opening javaw.exe to inbound connections from any IP is a security risk. You may wish to limit the scope of these rules to your local subnet. You can do this by double-clicking on the rule, and selecting Scope. Here, you can limit the remote IPs that can connect to javaw.exe to your local subnet (or specific IP addresses, if you choose).