Set PDF documents to open with Adobe Acrobat
1) In the search box next to the Start button, type the word "Default" and select "Default app settings."
Set the default PDF reader in Windows 10 to be Adobe Acrobat instead of Microsoft Edge, Google Chrome, etc.
2) That will open the Settings for Default Apps. Scroll down to the bottom of the window and select "Set Defaults by App."
3) Select Adobe Acrobat from the list on the left and then select "Manage"
4) Scroll down to .pdf and click on the application that is already set up as the default. Then click on Adobe Acrobat in order to change it as the new default application.
That will modify the PDF extension to now open with Adobe Acrobat instead of another application like Google Chrome, Microsoft Edge and so on.