I own a copy of Microsoft Office 2003, and here’s how I managed to install it under GNU/Linux (Debian) using Wine. Most versions of office 2003 install without problems, so this post does not apply. However, there are some versions (mine included), where the installer fails (i.e. it quits with an error).
The solution was to install an old version of Wine, namely Wine 1.2, from the Wine archives. If you have Wine installed, remove it (apt-get remove…) and install version 1.2 manually (dpkg). You can then install Office 2003 as expected.
Unfortunately using Wine 1.2, the activation of the software does not work. The solution here is to install the latest version of Wine in the Debian repository (apt-get install wine). Once Wine 1.4.1 is running, activating the software is no problem, and Office 2003 works.
(Yes, in an ideal world I would not need Microsoft Office, but LibreOffice cannot [yet] compete when it comes collaboratively work on Word files. It routinely messes up the layout, and regularly corrupts Word files when recording changes.)
Didier Ruedin 
I also need to get this working under linux; I have a legitimate copy of Office 2003; but activation fails for me due to Internet connection not being detected under wine. How did you get past the activation?
I’m afraid I don’t know more than what’s in the post. You’ll have more luck on sites on WINE. That said, you could always phone up Microsoft (that’s one way to activate Office).