In certain versions of Windows 10, you may receive a notification with a warning about Microsoft-verified apps when you run the Firefox installer.
This message is displayed because Firefox is not available in the Microsoft store. Any copy of Firefox downloaded from www.mozilla.org is safe to install, so choose "Install anyway".
If you do not see the option to “Install anyway”, follow the steps below to change your system settings.
- Open the Windows 10 start menu and select Settings.
- Click on Apps in the Windows Settings menu.
- In the Apps & features section go to Choose where to get apps, click on the dropdown menu below and select one of the options that allows you to install from Anywhere.