Installing outlook add-in every time user logs off

I have an Outlook add-in that is working fine for every client. They get the installation (ClickOnce) from the web, install it and run it without any problem. However, I just got this client that it's complaining about seeing that "Microsoft Office Customization Installer" window (and of course, downloading and installing the add-in again) every time he logs off and logs back (he can close outlook and re-op开发者_如何学编程en it without any issues). BTW, He is using a Terminal Services environment.

Does anyone have any idea why this is happening and/or how to solve it?

It is probably a policy or login script that removes any installed applications. You'd best talk to his system administrator.