Quote Originally Posted by ams View Post
If you want to make Acrobat your default program for PDF files, you need to bring up Acrobat and go the Edit/Preferences and then select General. At the bottom of the page you will see 'Select Default PDF handler'. Click on this and select Acrobat instead of Acrobat Reader. You will require a system reboot, but after that everything will be as you require.
This is the way to solve the problem -- it turns out that some distributed PDF forms REQUIRE using the free Reader DC and will not work with the paid-for Acrobat Pro. When both are installed it was a real pain to have everything open in reader, and this post solves the question. Thanks.