If you are not an admin and PDF24 is installed for your user then the profiles are (in Windows 10 x64) in: HKEY_CURRENT_USER\Software\PDFPrint\Profiles\fo
You can export the profile you want and import it somewhere else.
Stefan, is there any registry key to tell PDF24 that "SOMEPROFILE" should be the default loaded?
I know that it defaults to the last one used but this requires to at least select that profile and then exit 🙂