Make Firefox your default browser
If you have more than one web browser installed, any links that you click on will automatically open in your default browser. This is how to make Firefox your default browser.
Click the menu button, then choose Options.
In the General panel, click Make Default…
The Windows Settings app will open with the Choose default apps screen.
Scroll down and click the entry under Web browser.
Click on Firefox in the dialog that opens with a list of available browsers.
Firefox is now listed as your default browser.
Close the Settings window to save your changes.