Secure Your PC with Windows Firewall Windows Defender Firewall prevents unauthorized access by malware or Trojans to the PC when connected to the internet. To enable the firewall, type firewall in search box next to start button. Click on Public network Firewall On to enable the firewall You Might Also Like Secure your PC with Windows updates September 14, 2019 Premium Antivirus recommendations for Windows May 5, 2021 Free Antivirus recommendations for Windows May 7, 2021