Every "2000" series Microsoft product CD has a data1.msi file on it. So
if you had a Visio 2000 CD, there would be a data1.msi file on it, but
it's not the same data1.msi that comes with Office. Office 2000 came in
Standard, Small Business, Professional, and Premium versions, each with
a data1.msi on CD1, and each version's data1.msi is different from the
others. So while you have a data1.msi on the CD, it's not necessarily
the one that OfficeUpdate is looking for. That's why I asked whether
you had a preinstalled copy of Office or if you installed Office
yourself from your CD. If you installed Office yourself from your CDs,
then the data1.msi on your CD has to be the same as the one on your
computer, and it would be pointless to uninstall/reinstall.
Uninstalling won't delete the documents, spreadsheets, presentations,
etc., that you created with Office as long as you saved your work to a
separate folder that Office does not use for program files.
Uninstalling will delete Word .dot, .dic, and .acl files; Excel .xlt and
..xlb files; Powerpoint .pot files; Outlook .pst files (mail messages and
mail profiles); and probably a few other things I don't remember off the
top of my head. If you're planning on uninstalling and reinstalling, it
would be wise to do a full system backup (and make sure you can restore
from the backups... it's amazing how many people learn too late that
their backups are unusable!), and then you can easily recover any
missing files.