How to Activate a Firewall on Windows 2000
- 1). Click the Windows 2000 "Start" button and select "Run." Enter "gpedit.msc" and press "Enter." This opens the policy editor.
- 2). Click "Computer Configuration" to expand a list of options. Click "Administrative Templates," then "Network," then "Network Connections" and finally click "Windows Firewall." Click "Standard Profile" in your list of options for the firewall.
- 3). Double-click "Windows Firewall: Protect all network connections." Select "Enabled" to enable the firewall applications. Click "OK" to save the settings.
- 4). Reboot the computer. The next time you boot, the firewall will be enabled and activated on your computer.
Source...