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 Programs
Set the default PDF reader in Windows 10 to be Adobe Acrobat instead of Microsoft Edge
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 "Set this program as default"
That will modify the PDF extension to now open with Adobe Acrobat instead of Microsoft Edge.