Adobe Reader X install on a workstation with Adobe Acrobat

Question

I need to deploy Adobe Reader X to all users in our org (10,000+).  However, when testing the MSI on a machine with a previous version of Adobe Acrobat installed, Adobe Reader X becomes the default PDF handler.  I have made a change to the MST using the Customzation Wizard.  I have tried entering DEFAULT_VERB=OPEN in my command line.  I have edited the MSI directly using InstallShield.  In all cases, after the install Adobe Reader X is the default PDF handler.
This is unacceptable.  In previous versions, all that was necessary was to use the Customization Wizard and set the option to make Acrobat the default if it was installed.  The only valid option now is "Installer will decide which product will be the default."  I cannot deploy this application this way.  It makes no sense to have a user that has Acrobat installed to use Reader for opening PDF's!!!
Please assist.
JDAWG

Answer 1

Please see this link for an explanation of the value of co-installs, and the rationale for the PDF switcher registry keys.
In the Acrobat X Family, the DEFAULT_VERB parameter is replaced with IW_DEFAULT_VERB, values being "Read" (uses Reader) or "Open" (uses Acrobat). You can also set LEAVE_PDFOWNERSHIP="YES" to keep whatever existing handlers are registered (if none, the installer will claim them).