There was a microsoft update in October tha...

There was a microsoft update in October that invalidated my use of Office 2003. This is an authentic copy with all the holograms and registered with Microsoft last fall when I loaded it on my computer. I was working away from home at the time and did not have the CD with me. Ireturned home reinstalled the Office 2003, still same message about user. Tried a couple more times same result. Started having problems with windows. I downgraded from Vista to XP using the 2 CD's provided. I noticed last night however there is no product code on the CD's and I assume to use them as with all Microsoft products that it will ask for a product code. Can you tell me please what the code is to use the recovery CD's?