A firewall is one of the first lines of defense against existential threats to your device, and most operating systems include one in some form, so you have protection even if you don’t pay for robust antivirus tools. The built-in Windows Defender Firewall is surprisingly robust. Beneath its clunky interface lies a powerful packet filtering engine that does a respectable job of keeping unwanted elements out. However, one trip to the Advanced Security settings page reveals a travesty of tedious wizards to configure simple rules. For technophiles and home lab enthusiasts who want granular, explicit control over every packet leaving their machine to ensure a chatty smart device doesn’t contact a random server.