MS Office Problems under Guest ID

I am attempting to use the Guest ID on my system so someone else can use it
without exposing my personal files. When I login with the Guest ID and start
any MS Office application, it goes through an Install process automatically
and stops with an Error 25090 Office Source Engine System Error. I have tried
the fix on the MS Knowledgebase website but it hasn't fixed the problem.
Office is installed and functioning properly under the administrator ID. Are
there some security accesses I need to set up for the Guest ID or why does it
try to load the application when I try to open it? I am using XP Professional
and Office 2003 Professional.

By the way, after I respond to the errors, the application comes up. I
haven't tried using it though, I want to get this working properly first.