Have you done a port scan and realized that there are many open ports on your system? If you want to close open ports in Windows 7 you will need to configure your firewall.
Why some open ports are required
Many programs require open ports for communication with the outside world. How for example do you think does Bittorrent or your e-Mail software work? Exactly, specific ports are opened to transfer data via a specific internet protocol (Transmission Control Protocol (TCP), User Datagram Protocol (UDP) or IP (Internet Protocol).
Built-in Windows 7 firewall
So, if don’t want to give up your mail software or torrent client, you need a reliable firewall that will filter you network traffic and also close down open ports that are not needed. The built-in Windows 7 firewall is capable of closing ports:
Launch the firewall settings, then under advanced you will be able to edit the port policies and close ports in Windows 7.
The firewall already have many pre-definied rules how to handle specific connections, e.g. DNS (Port 53) or HTTP (Port 80), DHCP (Port 67).
A professional firewall can help you to close ports, some even provide a stealth mode that won’t allow people from the outside to find the ports. A