CCTK silent install issue

On Windows 7, when I attempt to install CCTK 2.1 using WPKG with the command "msiexec /i cctk.msi /qn" silently in the background, it fails with the following error in the syslog:

Product: Dell Client Configuration Toolkit -- Error 1401.Could not create key S-1-5-21-3275671095-1950649569-3952301132-121891\Software\Microsoft.  System error 87.  Verify that you have sufficient access to that key, or contact your support personnel.

However, when I do it from console, it installs without issue.

I'm running the installation from a Group Policy Preferences scheduled task, and from a "psexec -h", so it should have escalated privileges in both cases. In both cases it fails with the same error message.

Other programs install fine, and make significantly more intrusive changes to the registry without generating errors.

edit: It installs fine in XP.

edit: using Dell's installer instead of extracting the MSI, and specifying a logfile, has this line buried in it:

MSI (s) (80:B8) [15:48:51:318]: Product: Dell Client Configuration Toolkit -- Error 1401.Could not create key S-1-5-21-3275671095-1950649569-3952301132-121891\Software\Microsoft.  System error 87.  Verify that you have sufficient access to that key, or contact your support personnel.