With Office you have to have the original CD (or the files off of it) to
install the service packs. Just put the original office CD in the drive
then the update will work fine.
proplus.msi is the installation file used to install all office PROfessional
PLUS services, the msi file acts as an organizer and delivers all the
services (FrontPage, excel, word etc) to the directory you choose. But IT
DOES NOT COPY ITSELF, therefore everytime you upgrade or re-install the
product the proplus.msi will ask for this file. It's on the CD
