I am using Windows 10 1809 version for almost 6 months. PDFs keep reverting to edge although I revert it to Adobe Reader and make that the default many times after a few days notably after monthly cumulative updates windows 10 sets edge as a default for PDFs.
I have tried resetting the defaults then assigning Adobe as default, right-clicked and selected to always use adobe for these files but it reverts back after a little while.
I suspect your user profile could be corrupted try to delete the user profile and create a new one. Please follow the below steps to delete an existing user profile and create a new one.
- Login the PC with built-in administrator account
- Delete the temp user profile in C:\users\
- Delete the registry file for the temp user if available in the registry < HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList .>
- Goto c:\users and rename the default folder to something like default.old (note: you need to enable hidden files in the view to view this folder)
- This is the main step Copy the default folder (c:\users\default) from a good working computer and paste in the exact location (c:\users\default).
- Now restart your computer and log in.
Hope this helps