This article describes how to set Adobe Acrobat as the default program for working with PDFs. You can use the same process for setting default programs for other document types.
1. Right-click the windows icon and click 'Apps and Features' (you can also type 'apps and features' in the search bar beside the windows icon)
2. Select the 'Default Apps' tab on the left-hand side and click the 'Choose default apps by file type' link toward the bottom
3. Scroll down to .pdf and click the program that is currently listed beside it. You will see a drop-down menu asking you to choose an app. Click Adobe Acrobat to set it as the default, then you can close this dialog box and your choice will be saved.