I am having the EXACT same problem that is described above, only with AutoCAD. I am a net. tech for a school district, and our little hackers, I mean children have very restrictive accounts.
Ironically it is only AutoCAD that doesn't work. Inventor launches its setup and launches just fine. Autodesk architectural works just fine.
But when the student launches AutoCAD it throws the "you need admin " message.
Can you explain what can be done to get around this in greater detail?
By the way, strangely, if the user first launches AutoCAD, it gives that error, but if they first launch inventor, close it, they can then launch AutoCAD.....