Page 699 - Windows 10 May 2019 Update The Missing Manual: The Book That Should Have Been in the Box

routers have hardware firewalls built right in, protecting your entire

network.

Still, there’s no harm in having both a hardware and a software firewall in
place. In fact, having the Windows Defender Firewall turned on protects
you from viruses you catch from other people on your own network (even

though you’re both “behind” the router’s firewall). And if you have a
laptop, this way you won’t have to remember to turn the firewall on when
you leave your home network.

For each kind of network, you can also turn on “Block all incoming
connections, including those in the list of allowed apps.” When you turn on
this especially conservative option, your computer is pretty much

completely shut off from the internet except for web browsing, email, and
instant messaging.

Allow an app through firewall

The firewall isn’t always your friend. It can occasionally block a perfectly

harmless program from communicating with the outside world—a chat
program or a game that you can play across the internet, for example.

Fortunately, whenever that happens, Windows lets you know with a

message that says “Windows Defender Firewall has blocked some features
of this program.” Most of the time, you know exactly what program it’s

talking about, because it’s a program you just opened yourself—a program
you installed that might legitimately need internet access. In other words,
it’s not some rogue spyware on your machine trying to talk to the mother
ship. Click “Allow access” and get on with your life.