Ohio University

Both Windows and Macintosh systems have built-in firewalls. For the majority of personal computer users, these firewalls represent a good compromise between easy to use and security.  

Enabling Windows Firewall

1. In the Control Panel, click 'System and Security'.
   
2. Choose 'Windows Firewall'.
3. In the Control Panel Home, choose 'Turn Windows Firewall on or off.'
4. Make sure they are set to 'On'.
   
5. Click 'Ok'.

To Ensure Your Windows Firewall is Active

1. Go to your Control Panel.
2. Click on 'System and Security.'
3. Click on 'Check Firewall Status.'
4. If it says 'On', the Firewall is already active

Enabling Macintosh Firewall

1. Go to the Apple menu and select 'System Preferences.'
   
2. Choose 'Sharing' under 'Internet and Network.'
3. Choose Firewall.
4. Click start to enable a new firewall.
   
5. Place a check in boxes for any ports you wish to allow traffic from.
6. Close the window when you are finished.

To Ensure Your Macintosh Firewall is Active

1. Click on the Apple and select 'System Preferences.'
   
2. Double click on 'Sharing'.
3. Choose the 'Firewall' tab.
4. If it says 'On', the Firewall is already active.
   

Note: If you decide to install a third party firewall on your computer, you should disable your operating system's built-in firewall. There should never be more than one firewall enabled on a single computer. Also, installing a third-party firewall can have unexpected side effects, including an inability to access the Internet. Be prepared to do a bit of troubleshooting if you choose to go beyond using the basic, built-in firewall that comes with your operating system.