There are hundred of guides which teach different methods to forward ports, but it is still difficult for those who are new to this concept. This is where Simple Port Forwarding comes in, it is a free utility that lets you forward ports instantly without having to learn too much about networking.
I was having a connection problem while playing Far Cry 2 online, so I used this tool to forward my port easily. Here is how you can do it too. Simply run the program and select the router from the list, it supports almost every router out there in the market, if you think your router is not listed you can contact the developer and he will add it in later release. Now enter your your Router IP, username, and password and click the + button(Add New Port To Forward button) as shown in the screenshot below.
A new window will open where you can add any program name who’s port you want to forward and also enter the TCP/UDP details. Since an ordinary person does not know what is TCP/UDP and which value he should enter, have a look at the list of common ports where you will find details on every program and game. Once you have entered the details, click Add.
Before you add a custom port to forward, click Database tab and check if the program whose port you want to forward is listed(about 677 programs are in the list). If it is listed then it will save you a lot of headache, since it will automatically enter the TCP/UDP details too.
Once you have added the programs whose port you want to forward, click Update Router and you are done.
This tool works on all versions of Windows. Enjoy!