Windows has a firewall built into the operating system and this is usually enabled by default, unless you have a separate firewall installed. But, occasionally, your firewall can become disabled.
This can happen if you install, then uninstall, a third-party security suite that has its own firewall. For the security of your PC, it’s worth checking that your firewall is on.
How to enable the Windows Firewall
Open the Control Panel and click System and Security, then Action Center (Windows 7) or Security and Maintenance (Windows 10).
Next, click the down-arrow next to Security. Under Network Firewall, you should see a message saying that Windows Firewall (or any third-party firewall that you have installed) is enabled and protecting your PC.
If the Windows Firewall is switched off and you don’t have a separate firewall, click Start, type firewall and click Windows Firewall. Next, click Turn Windows Firewall on or off > Turn on Windows Firewall then OK.
Read our tips on how to allow or block programs with the Windows Firewall