Running the monthly update, there were no updates for MS Office 2003 even though there are at least two which are available to Vista. One update (KB975958) is an update to the Outlook Junk mail filter. The other was KB 975958.
Have you received Office updates previously? If not, then open any of the products (Word, Excel). Select Help from Menus, and check for updates. It will then give you the option to get Office updates thru Windows Update.
The problem is that the Junk Mail Filter update for November does not state that it can be used for Win 7.
Even KB973475 (Excel 2003) excludes Win 7.
Under Vista I had no problem.
Check for updates under Help is of no value as it opens the Office Update page which only allows each individual updates as a separate download. But then it never states that Win 7 is okay with the update.