How to find what program used as default for opening file .xyz ?

In cmd type C:\> assoc .xyz which program will open that .xyz file

Install IE

To open Internet Explorer, select Start Windows logo Start button, and enter Internet Explorer in Search Magnifying glass Search icon. Select Internet Explorer (Desktop app) from the results.

If you can't find Internet Explorer on your device, you'll need to add it as a feature. Select Start Windows logo Start button > Search Magnifying glass Search icon, and enter Windows features.

Select Turn Windows features on or off from the results and make sure the box next to Internet Explorer 11 is selected. Select OK, and restart your device. Tip: You can pin your favorite apps to the taskbar. Open the app or program, press and hold (or right-click) the icon on the taskbar, and select Pin to taskbar