We can use properties to set Adobe Acrobat not to take ownership of the default PDF file extension, by leaving Adobe Reader as the default PDF reader.
For version 10.0 & higher use the property LEAVE_PDFOWNERSHIP=YES
YES - prevents the new installation from taking over PDF ownership.
NO - allows the new install to own opening PDFs.
For version 11.0 & higher use the property OWNERSHIP_STATE=0.
0: Do not take ownership.
1: Take ownership for the current user.
2: Take ownership for all existing and new users.