Hiding the C: drive in Office 2000

I have user policies in place which hide the C: drive in “My Computer”, Explorer, etc. I have also hiden Run from the Start Menu. However, when a user performs any actions under file (such as “save as” or “open”) with any Office 2000 product, theythen can see and have access to the C: drive. How can I prevent this from happening because it totally negates the purpose of my user policy. Please help.