According to the SP3 download page,

http://www.microsoft.com/downloads/details.aspx?FamilyID=5C011C70-47D0-4306-9FA4-8E92D36332FE&displaylang=en

you should have SP1a before installing SP3. Although SP1 should be the same, as far as Word is concerned, (and the 'a' does not show in the help/about box) you could check what you have

http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/kb/articles/Q261/9/34.asp&NoWebContent=1

Or just try first installing SP1a (if nothing needs to be installed it will not matter, but it might put an msi file on your drive).

Alternatively, in the first link, it lists the individual updates that SP3 replaces. Only some apply to Word and you could try downloading those instead. I guess that since you mentioned the Works CD, your copy of Word came with Works rather than Office. So the bits in SP3 that relate to other parts of Office (Excel, Outlook etc.) would not apply to you.

Thanks for the advice, but I'm still unable to resolve this problem.  I downloaded the Office 2000 Service Release 1a (SR-1a), o2ksr1a.exe, from:

http://www.microsoft.com/downloads/details.aspx?FamilyID=AF6C8D03-7633-45B4-AB96-795EE656F2A2&displaylang=EN

Unfortunately, it gave the message, "You already have Microsoft Office 2000 SR-1."  The lack of the "a" after "SR-1" only leads me to be more confused.

Following this, I re-ran Office 2000 SP3, with the same results as before.

Doug