Making Adobe Acrobat Reader your Default PDF Viewer

Navigate to the start menu and type in Control Panel to find the control panel icon

Click Control Panel

In the search bar in the top right, Search Control Panel for "Default Programs"

Click Set your default programs

Choose default apps by file type

Scroll down to .PDF file and click the box of the file.

Select Adobe Acrobat Reader or your preferred PDF viewer if you have a different preference installed.