Microsoft Edge keeps making itself the default PDF viewer instead of acrobat

Not sure if this will work for everyone, but this is what I did after everything else failed:

Control Panel>Programs and Features> Select Microsoft Edge - Click on change ("Uninstall" is not an option that is offered). Then repair.

While the change/repair is underway, do this:
Settings>Apps>Default apps>Adobe Acroboat - click on .pdf and change to Adobe Acrobat as default.
... and it worked!

I hope it does not for the rest of you too.

FYI - not a nerd, so, please don't shoot me for trying to help. I rummaged through several sites first, and tried everything that was suggested and failed.

We are also using Roaming Profiles that the get loaded for every RDS user session and deleted from the RDS server again on logout.

The issue in this case is that the Windows Explorer treats every user a a new one and takes actions to initialize the profile (despite the roaming profile being actually loaded).

One can see this in the Microsoft-Windows-Shell-Core/AppDefaults event log.

We have this group policy enabled to prevent this behaviour:

Up to at least Server 2012R2 ithad the desired effect. But since Server 2022 (maybe earlier) this policy seems to be ignored by Windows Explorer. This is the root cause of the issue.

To work around, we simply cleared all associations from the exported C:\DefaultAssociations.xml before importing it again. (We are manging the desired associations with the "Set a default associations configuration file" group policy.)

Adding my voice to this problem as well. Trying to build a 2022 RDS Session host and after every login, Edge is taking over PDF file associations. But only for non-admin users.

Well, I seem to have fixed it. Setting the PDF handler, exporting the associations using DISM, and reimporting them with my admin account seemed to fix it for all users on subsequent logins. Edge no longer takes over the association on each login.

Dism.exe /online /Export-DefaultAppAssociations:C:\DefaultAssociations.xml

Dism.exe /online /Import-DefaultAppAssociations:C:\DefaultAssociations.xml

https://techcommunity.microsoft.com/t5/ask-the-performance-team/how-to-configure-file-associations-for-it-pros/ba-p/1313151

THIS SIMPLY DOESNT WORK.

I have tried all the advice about stopping Edge from hijacking PDF files and nothing works. After I set Acrobat to be the default program for PDF files, sometimes, within an hour, Edge has made itself the default browser again.

This is insufferable

We are encountering the same issue where I work, and I have a GPO linked to a defaultassociation.xml file to govern application defaults and Edge still does this after every major update. I have to redefine the default app association for PDF docs, re-export a default app XML file to retain the settings. It will happen again though after the next major update release.... Getting REAL ANNOYING to have a patch override explicitly defined parameters defined by a GPO, following suggested MS best practices........

Microsoft, what use is it to define default associations via GPO if your browser keeps over riding one of the file associations after every major update?