To protect the security of the computer, in addition to anti-virus software, another means is a firewall. The firewall has two main purposes: 1) To resist the attack of the external network on the local computer; 2) To effectively control the access of the local program to the Internet. It's a pity that Windows' built-in firewall has a single function and poor usability, so there are a large number of third-party firewall programs. Of course, all third-party firewalls implement corresponding functions based on the operating mechanism of Windows' built-in firewall.

If we use the built-in firewall of Windows to prevent the specified programs from connecting to the Internet, we need four steps at least: 1) Enter the Control Panel; 2) Open Windows Firewall; 3) Click Advanced settings; 4) Add new rules. If you want to simplify firewall operation (preferably one-click) and can't stand the high system resources occupancy of third-party firewalls, then Firewall App Blocker is probably what you're looking for!