Small Bussiness 2007 can't find a version of MS Office

Progressive installs range from Works ver 7.0, 2000 Pro, 2003 Pro Enterprise
and now 2007 Small Business. Works and 2003 have all of the latest updates
.... and are listed as qualified for 2007 update (as were the other Office
products).

After entering CD key, install gives reply: "setup can't find a version of
MS Office on your computer" ... display gives a 'browse' button, and no
matter what path I insert receive this message: "the path you have chosen
doesn't point at a qualifying upgrade product".

I've tried 'swapping' OEM 2000 and 2003 CD ... to no avail - even copied all
of the files to hard drive - Nothing!

Am running Vista in Admin account ... have pointed to Msocache\All User
folder (everything) - Nothing!