Windows will allow you to set the default program you want to use for certain file types. This comes in handy many times when your internet browser hijacks your PDF viewer.
From your Start Menu, start typing Default App Settings and click on the app when you see it in the menu. Toward the bottom of the screen, you’ll find a link to “Set defaults by app.”
From there, you can select the program you want to use for a particular file type (i.e Adobe Acrobat Reader for PDF files). Select the default program and click the Manage button.
Finally, pick the file type you want associated with the program you selected and update it to the program you want to use.