Setting Internet Explorer 11 as your default browser in Windows 10
When you upgraded to Windows 10 if you agreed to use the "recommended defaults" setting during the installation, Windows 10 will automatically change many of the default programs associated with certain file types. In this case, Microsoft Edge became your default web browser by using the recommended defaults.
The good news is that you can easily change the default browser in Windows 10 with a few mouse clicks, though the way this is done is a little different than how it was managed in Windows 7.
Best Option: Change your Default Web Browser using the Settings App
This is the most common method used for changing your default browser and should work in most cases.
Click Start and type in "default browser" (no quotes).
Click the link that says "Choose a default web browser" when it appears in the list of your Start menu.
The Settings window will appear; click the "Default apps" heading on the left (it should already be highlighted).
On the right of the screen, look for the heading "Web browser" and click the icon.
A new window will appear with the title "Choose an app". Select Internet Explorer 11 or whichever browser you wish to use as your default.
How to Run Internet Explorer 11 from the Start Menu
By default Internet Explorer 11 is hidden from the Start menu. You can access is by clicking on Start, then type in "Internet Explorer" (no quotes); once it appears in the list, you can right click it and select "Pin to Start" or "Pin to Taskbar".