Firefox is one of the best browsers to use, In case if you don’t know how to make it as your default browser try following the below steps to make it as your default browser.
1. Go to options in the “Tools” menu bar (or) by clicking on firefox drop down menu.
2. In the options window go to “Advanced” tab and select “General” sub tab, There you can find an option to make Firefox as default browswer.
3. AsĀ soon as you select “Make Firefox as Default Browser” it must be set as your default browser or it will open up the default applications window where you manually need to select Firefox application on left bar and select on make it as default program in right hand side bar.
Note : Do not confuse with the name “Nightly” , It is a version of Firefox developed by mozilla team to speed up the prorcess of building firefox.