Setup for Office, iTunes, etc runs for all users other than origin

Using Vista Home Premium and recently whenever users other than the original
one I set up launches some of the apps (such as Word 2007 and iTunes) setup
initiates and the product has to install. With iTunes, it never completes
successfully, but with Office, the app eventually launches successfully.

Any ideas? The initial ID works fine. I granted Administrator access to all
ID's and still have the same problem.

Thanks!