What does "Windows Firewall Has Blocked Some Features" mean?

The short answer

Windows is telling you that an app tried to communicate over the network, and the firewall stepped in to block it until you decide whether to allow it.

Why does this happen?

Windows Firewall monitors all programs that try to send or receive data over your network or the internet. When an app attempts this for the first time and doesn’t already have permission, Windows pauses it and asks you what to do.

Common triggers include:

Installing a new app that needs internet access, like a game or video call software
Running a server or hosting tool such as a local web server or multiplayer game
Software updates that need to phone home to check for new versions
Remote access tools like remote desktop or file sharing apps

Should you allow or block it?

That depends on whether you recognize and trust the app.

Allow access if:

You just opened the app yourself and expected it to connect online
It’s a well-known program like Zoom, Steam, Slack, or a web browser
The app needs the internet to work, like a multiplayer game or cloud storage tool

Block access if:

You don’t recognize the program making the request
You didn’t open anything that should need network access
The app name looks suspicious or misspelled

How to change your decision later

If you blocked something by mistake, or want to revoke access you previously granted:

Open Settings and go to Privacy & Security then Windows Security
Click Firewall & network protection
Select Allow an app through firewall
Find the app in the list and check or uncheck the boxes to change access

When should you worry?

Most of the time, this notification is completely normal. But pay attention if you see it pop up when you haven’t opened any new apps, or if the program name looks unfamiliar. That could be a sign of unwanted software trying to reach the internet. In that case, block it and run a malware scan to be safe.