
Hello, GeneDryden
Welcome to the Microsoft community.
Thank you for your feedback. You can try the following programs:
Open Run (Win + R).
Type regedit and press Enter to open the Registry Editor.
Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts.pdf.
Modify the “OpenWithProgids” item to set the default application value to the preferred PDF reader.
If necessary, you can also make the appropriate changes in HKEY_CLASSES_ROOT.pdf.
Modifying the registry may pose a risk to your system, so make sure you understand the changes you are making and Back up your registry ahead of time.
Open the Command Prompt (Administrator).
Use the assoc .pdf=AcroExch.Document command to associate a PDF file with Adobe Reader (Adobe Reader for example).
Document=“C:\Path\to\your\PDF\reader.exe” %1 command to specify the default program path.
If the above methods do not work, you can try to reset your PC by clicking System, Recovery, Reset this computer without keeping the files.
Backup your important data before doing this operation.
Please let me know if you have any other questions or if I haven't explained something clearly.
Best Regards,
Aaron | Microsoft Community Support Specialist