This is driving me mental....
New Windows 2019 Remote Desktop Server. One user requires Adobe Acrobat Pro, all other users just Acrobat Reader. So we have both installed, and restrict all other users from running Acrobat Pro via GPO settings (since we only have a single license, we want to ensure no other users can use Pro).
Adobe Reader is set as the default PDF application, and this all works perfectly - except for Quick Print in Outlook, which insists on trying to use Acrobat Pro.
I have replicated the setup on a Windows 10 PC and the same issue happens.
I assume there must be a registry key or setting that sets what app Outlook uses for Quick Print, but I've spent hours trying various things and have made zero progress.