Use Wise Package Studio's InstallTailor to create an MST for the vendor-supplied MSI file, being sure to select the "Install for All Users" option.
In Wise Package Studio's Windows Installer Editor, select "MSI Script" and click the "Execute Immediate" tab.
Just below the "InstallFinalize" instruction, insert an "If not Installed then" instruction, followed by two "Call VBScript from Embedded Code" instructions, and an "End" instruction.
The first embedded VBScript should use the subinacl tool to give users read/write permission to the key:
The second embedded VBScript should use the CACLS tool to give users read/write permission to the directories:
c:\Program Files\Common Files\Business Objects
c:\Program Files\Business Objects
Note that the above permissions changes are really only necessary if your users won't have administrator access on their machines. In our environment, users do no generally have administrator or power user access, so we need to specifically grant them permissions to change files and directories when it's necessary for an app to function.