1. Turn on your firewall

Activating the Windows 7 firewall

A firewall protects your computer from Internet worms that exploit open ports and operating system vulnerabilities. Only one firewall should be active on a computer.

If the Windows Security Center reports that your firewall is off, turn it on following these steps: 

  1. Click Control Panel > System and Security > Windows Firewall.
  2. In the left-hand column, click Turn Windows Firewall on or off.
  3. Click Turn on Windows Firewall (in both network settings locations).
  4. Click OK.
  5. Close the Windows Firewall window.