Office XP w/multiple users on the same computer w/WinXP

[Brett]

I am running Office XP on computers with Windows XP. I have multiple users
that share a single machine, but when each person logs on with thier own
user ID, office is not installed for each user. If I try and open office
manually, it says that office is not installed for this user and they have
to install it. So everytime a new user logs on they have to install office
again. If an old user logs on, it is still there.

Hopfully simple, but I would be greatfull for any ideas!
thank you
Brett