Windows Vista Firewall

Windows Vista has a built-in firewall. This can help raise the level of security for your computer when it is connected to the Internet.

Select Start | Control Panel. Once you are inside the Control Panel, click on Windows Firewall.

The Windows Firewall status window display. To change Windows Firewall settings, click Change Settings.
The General tab allows you to turn on or off the Windows Firewall. If you would like to set some advanced settings - such as opening a port for a server - click on the Exceptions tab and place a check in the box(es) next to the program(s) you wish to open. To add a new program, click the Add program... button.
When you are finished, click the OK button to return to the Control Panel.