If Windows Firewall is not enough for you then you should give PrivateFirewall a try. It is a free advanced firewall for Windows that filters all internet and network traffic. Not only this, but it also prevents any new application or process from launching unless you approve it. Want to monitor applications, processes, and ports? Its all in there. What makes it great is that it fully integrates in Windows Security Center, thus giving you better overall protection even if you are using Windows Vista or Windows 7.
On the main window you will find three different types of settings – first straight up there is a general setting to adjust Internet and Network Security, then there are three lights on the upper-right corner from where you can deny all traffic, allow all traffic, or filter the traffic, and finally there are three different types of profiles(Home, Office, and Remote Profile), each suitable for a different environment.
Note: Once you install private firewall your internet might stop working, you will need to hit the green light as shown in the screenshot below to allow all traffic and then set the desired settings before filtering the setting again by hitting the yellow light.
If you are a network administrator, you can also block all outgoing emails over the network simply by hitting the Block Outbound Email button. To view all applications and processes that are trying to access the internet, hit their respective buttons from the left sidebar.
You can also view the log file for the firewall or simple click Port Tracking button from the left sidebar to view all ports that are listening to connections.
If you simply want to add an extra layer of security or just want to get complete control over all the internet and network connections, then this tool does the job really well.
Warning: Blocking some important process from accessing the internet might render some applications useless. So be careful what you block/filter/allow.
It works on all Windows 2000, XP, Vista, and 7 (both 32 and 64-bit OS are supported). Enjoy!