In an increasingly connected world, an indispensable component for all computers is the Firewall, that is the tool that filters inbound and outbound connections, blocking unauthorized access to malicious programs and intruders. Not knowing how to adjust the firewall will inevitably lead to an intrusion or a heavy infection on the PC, perhaps because it has always confirmed itself as Yes without checking what we were providing access to.In order to understand how this very important security tool works, we will show you in this guide how to activate, control and manage the Windows Firewall in a simple way; if we are already more experienced users, we will also show you how to access the advanced firewall control panel and how to re-enable Windows Firewall in case of blockages or problems. All the steps described have been carried out for the Windows 10 and Windows 11 firewall (nothing changes), which is the most popular operating system: many commands and screens, however, can also be found on old operating systems, that is Windows 8.1 and Windows 7.
How to activate and check the Windows Firewall
If we are novice users and / or do not know anything about how a firewall works, we click at the bottom left on the Start menu and click on the gear button, so as to open the Window 10 settings. in the path Update and Security -> Windows Security -> Firewall and Network Protection. We will find ourselves in the simplified Windows integrated firewall management screen.
To verify that the firewall is active, click on the currently active network (indicated as active among the three available items), then make sure that the check mark is present On in the section Windows Defender Firewall. For added security, make sure the same voice is also active in the types of networks you don't currently use (usually Domain network e Public network).
If we want to check if an app has been allowed to access the Internet or if we want to block any connection, just click on the item Allow apps through firewall.
In the new window we click on Change settings at the top right, then scroll through the list until we find the app that's right for us. To authorize access to the computer, we will need to check the columns private e Public (or even just one of these, to prevent some apps from working under hotspots), or remove all check marks, so as to block the application (who will no longer be able to access the Internet).
If the app or program is not listed, simply search for its executable by clicking on Allow another app, so as to add it to this list.
Note: many apps signed and recognized by Microsoft configure themselves automatically, without user intervention (they apply by themselves the necessary permissions to navigate correctly. If, on the other hand, we run an unknown or unsigned app, we will be shown a Windows warning window Firewall, where we can choose whether to authorize access on private networks and / or public networks (according to our needs), by placing a check mark on the items Private networks o Public networks and clicking on Allow access.
To block Internet access from this screen, simply remove both check marks from the warning window and click Cancel.
If a sudden attack or infection threatens the PC, we can immediately block every connection by taking us to the Settings menu and the path Update and Security -> Windows Security -> Firewall and Network Protection, by clicking on the type of network marked as active and checking the box Block all incoming connections, including those in the list of allowed apps.
A "shutter" will be lowered on our computer and no program will be able to access the Internet, even those authorized.
How to configure Windows Firewall in advanced mode
If we are already experienced users of Windows but do not know how to configure the firewall as a real network administrator, here we will show you how to do it.First we open the Start menu at the bottom left and look for Windows Firewall, taking care to select Windows Defender Firewall with Advanced Security.
From this screen we can check the authorized incoming and outgoing connections by clicking on the respective items Inbound Connection Rules e Outbound Connection Rules, as well as checking the security rules for individual connections, by clicking Connection security rules.
To get a summary picture of what is authorized or not for the type of connection in use, click on Monitoring, then on the item View active firewall rules.
Once we have identified a suspicious process or program to block, right-click on its rule (present in Inbound Connection Rules e Outbound Connection Rules), we select Property and, in section Operation, we choose how to behave between Allow the connection, Allow connection only if secure e Block the connection.
Let's click Apply e OK to confirm the change. Remember that each type of network has its own rules: to make the change specific for a single type of network (or for all), right-click on the changed rule, go to the Advanced tab and remove (or remove) the check mark to one of the environments available between Mastery, Private e Public.
To add a new rule for a program, right-click on Inbound Connection Rules o Outbound Connection Rules, then click New rule. In the window that opens, we choose the type of rule to be inserted, enter the program path, the type of operation to set (whether or not to allow access), on what type of network to apply it and finally the name of the rule. When finished, click on end to add our own rule.
How to re-enable Windows Firewall
When the PC or some program cannot connect to the internet there may be a Firewall configuration problem.To quickly solve all the problems (by canceling the changes and additions of rules made up to that moment), we can reset the Windows Firewall by clicking on the Start menu at the bottom left, searching for Windows Firewall and selecting the item Windows Defender Firewall with Advanced Security. From the window that opens, make sure that the item is selected Windows Defender Firewall with Advanced Security at the top left, then click on the item Restore default policyThis time on the right side, a warning window will appear, which you can confirm the change by clicking on Yes.
In a few seconds Windows Firewall will be restored to its original configuration, as just installed.
If for some reason (perhaps a virus) the firewall management window does not open and you are unable to reactivate it or restore it, click on the Start menu at the bottom left, look for the Command Prompt, right click on of it, we select Run as administrator and, in the dark window that will appear, we enter the following command.
netsh advfirewall reset
Conclusions
Correctly configuring the firewall will allow you to protect our operating system and our data from external attacks and viruses, especially if we grant access permissions with the right attention.
If we are looking for good alternatives to the firewall built into Windows, we recommend that you read our guide to Best Free Firewalls for Windows PCs, where we can find the third-party firewall suitable to increase our security.
Do we use a Mac? Even if there are fewer viruses, it is better to protect your Mac or MacBook from hackers by raising an impassable "wall of fire", as described in our guide on How to activate the firewall on Mac.
