Seems to be a rather common problem. You're sure that you didn't install (a component of) Office 2003 or Office 2010? Just shrinking a partition shouldn't cause it, because it isn't supposed to change anything in the contents of any file.
Anyway, https://www.google.com/search?q=office+2007+always+configures gives a LOT of hits. Maybe a hit on one of the first pages gives a solution that works for you.
I have used Office without any hassle for several years in Win7, but recently I re-arranged the content of the hard drive so that downloads would go into a separate partition. Since then, when I want to open a WORD or EXCEL file, there is minutes of delay while Office 'configures' itself. How can I restore proper functioning ?