Hi,
I know there are/have been several iterations of this question. I have attempted ALL of the suggested fixes and none have worked. Its amazing. I have Windows 10 Enterprise x64 1709 with the latest version of Adobe Reader DC installed in computer labs. Each time someone logs in, they get a prompt indicating MS Edge has been made the default for pretty much everything. If Adobe Reader DC is opened, a prompt appears asking the user to make it the default, which goes into the process of making it the default in Windows. Something that will be undone the next time someone logs in.
I have tried:
Using a default apps XML file. I followed the instructions here pertaining to the XML file with no success. My difference being the path indicated within group policy does not exist for me. I used the GPO to create the aforementioned registry entry. No luck...
Installed the Adobe Reader GPO extensions on my DC's central store. All of the desired configuration settings are there, Adobe Reader DC/Windows just seems to be ignoring them. Not a single specified setting is applied.
Set the bShowInstallFTE and bToggleFTE user keys in the registry via GPO. This also has no effect.
I am completely at a loss. All I want is for Adobe Reader DC to be the default PDF handler and to not ask about or be changed by Windows 10. Pretty simple. My only success has been with creating a customized default user profile and copying to the default with sysprep and CopyProfile. It works, but it balloons the that new default user profile by hundreds of MB. This adds-on to the already lengthy time it takes for a new Windows 10 user to log in to over two minutes. That's on a PC w/16GB of RAM, Core i7 CPU and an SSD. Windows 7 did not have nearly close to this many problems with Adobe Reader.
Thanks