Just installed Office to discover that the Key I used has been used too many times and the activation fails. Follow the either of the two instructions below to allow you to put in an alternative key (if you have one!).
If you are using a 64-bit operating system then Office detects it and install slightly differently. The registry key(s) on 64-bit are at
Mike’s Blog that explains how to do this (http://bloggingabout.net/blogs/mglaser/archive/2006/12/12/Change-Office-2007-Product-Key.aspx)
the Microsoft KB Article ‘How to change the product key for Office XP, for Office 2003, and for the 2007 Office system’ (http://support.microsoft.com/default.aspx/kb/895456)