Download Net Defender
Net Defender allows the user to configure the program and create a filter to decide which programs can runs and which ones can't in the system. It also scans the ports that are open in you windows Operating System. It will close any port that is no being used and that represents a danger for your computer.
It's easy to configure and install, and pretty much everyone can use it and handle it.
It contains a feature that permits the user to block unwanted applications such as messenger or facebook.
This software is completely free and is compatible with Windows 7 as well as older versions of Windows OS.