A firewall is software or hardware that checks information that comes from the Internet or from a network. Then, the firewall either blocks the information or lets the information pass through to your computer. Whether information is blocked or passed through depends on your firewall settings.
A firewall can help prevent malicious software (such as worms) from gaining access to your computer through a network or the Internet. A firewall can also help stop your computer from sending malicious software to other computers.
Windows XP
To enable Windows Firewall,
Click Start, click Run, type Firewall.cpl, and then click OK. On the General tab, click On (recommended). Click OK again.
To disable Windows Firewall,
Click Start, click Run, type Firewall.cpl, and then click OK. On the General tab, click Off (not recommended). Click OK again.
Windows Server 2012
For Windows Server 2012, open the Server Manager and go to Local Server. Click on the link next to Windows Firewall.
To turn on or off, click on the Turn Windows Firewall on or off.
You can modify the firewall settings for private and public network. Either turning on/off for both or just turning on the public network firewall.
Note
• If the General tab or the On (recommended) option is unavailable, the system may have a policy against running the firewall. Contact the system administrator for more information about how to enable the firewall. In addition, the system may already be running a third-party firewall (Zone Alarm or Norton Internet Security, for example). Contact the system administrator for help in determining whether a firewall is already running on the system.
• When you turn off the firewall, you leave your computer vulnerable to attack. Therefore, before you turn off your firewall, disconnect your computer from all networks. This includes the Internet. Or, you can enable a third-party firewall.
