I'm logged in with an account that is a local admin in a Windows 2003 R2 SP1 server that is part of a SBS 2003 domain.
I'm running a .exe file that is an InstaShield Wizard to install an upgrade to a product. It extracts a few files, and then the Windows Installer window says "Preparing to install... " and after a minute or so we get this error window:
The system administrator has set policies to prevent this installation
Now, I have been able to install other products here, particularly the previous version of the product which I am upgrading.