This installation I am attempting has a rather convoluted history. I first bought an upgrade copy of Office2007 on Ebay - I already had Office97 so I expected that an upgrade would be OK. However, when I tried to install it, it told me that Office97 was too old (or words to that effect) and it couldn't be upgraded - I had to find something younger. So I then bought Office2003, installed it on my older computer running XP Pro, and had no difficulty installing 2003 and subsequently upgrading to 2007.
But it appears that Vista has other ideas. I can't see any reason why I shouldn't be able to use the same 2003 disk a second time - there can't be any notification to the disk that it has been used once, because the computer I used it in last time didn't have a DVD or CD write facility.
However, I think I have sorted it now, thanks to your "elevated command prompt" message - it must have done something. Previously, when I received the error message, the options were Abort, Retry, and Ignore. The latter two did nothing, but the Abort choice rolled the installation back to zero. This time, using the Ignore choice I was able to complete the installation, although some features didn't work. However, it was enough to allow installation of 2007.
I didn't consider downloading a trial version of 2007 because I assumed that it wouldn't accept the upgrade version I have.
Many thanks for your assistance, and may you have many hundreds of grandchildren.
Regards - Keith Caple