XP Home My Computer/Explorer no drives

I have a client that when you look at her PC with My Computer or Windows Explorer you can see the shared folders, Control Panel, but no drives. Not even the floppy. I switch users and I can see them. Both users are computer admins. I need to know 1. How to do this (I have some clients that might want to do this) and 2. How to undo it so my client can see her drives. Thanks in advance.