Updating clients on a Windows Vista machine

We have started using computers that have Windows Vista installed and
yesterday was our first update to the system since then. On Windows XP
machines we could change the security permissions on the client folder,
to allow the users to download and install the updated client without
supports help. However, the Vista machines still prompt for permission
elevation to update the client.

Has anyone found a way to allow the Windows Vista users to update their
own client without granting them administrator rights on the local
machine?

We are running Epicor 9, but I believe this is more of a Windows Vista
problem.