How to stop automatic install promt of Office 2003 Professional?

My mother believed she had accidentally uninstalled Office 2003 on her
computer (running XP). I found that it was not deleted and all of the office
programs work, but I cannot stop the automatic re-install dialog that pops up
whenever using an office program.
The reinstall then states that file SKU011.CAB is missing and to insert the
CD to reinstall. She has lost the CD, but since everything works does she
need a reinstall? The main issue seems to be stopping the install prompt-
which is popping up constantly and prevents work from getting done
..
I'm no expert (and am just helping out where I can) and have no idea how to
stop this install prompt. Any advice/help would be most appreciated. Thanks.