I have a client that is interested in upgrading around 5+ of their computers to Windows 7. They currently have MS Office 2007 installed on all systems. I doubt they are going to want to also purchase Office 2010 licenses. If we move forward with doing a clean install of Windows 7 on several of their machines, how can we reinstall Office 2007 for them without having to pay for it again? I'm not betting on them having any of the original disks or license keys. Is there a way to find out the current software keys and re-use them on the same computers? Any way to do this??