Heaton,
I don't believe you will be too successful using MSI to do this... Although the MSI service can run with elevated privledges, the device installer services you would require (Config Manager, Device Loader, and various other Kernel services) use the security settings of the user logged in to determine if they can perform their jobs. Thats why you can pre-install the INF, yet the install will still fail if the user doesn't have proper access rights.
You might be able to tweak the user settings in NT to get around this... but that defeats the whole purpose of not allowing users to install whatever HW they want.
For us -- under Windows 2000 -- we require a user to have admin rights to install our software for this vary reason.
I think under Windows XP, there maybe a slight modification to this behavior in regards to if the drivers you are installing has WHQL certification (and a corresponding Catalog (*.cat) file) a regular Joe user could install it on the system, but I'm not totally sure...
(Edited by Gripper4Hire at 3:50 pm on July 16, 2001)