From MS website: Please note: All users of the Windows 7 Release Candidate (including Windows Vista users who have upgraded to the Release Candidate) must do a clean installation of Windows 7 RTM. Please keep this is mind as you consider downloading the Release Candidate as opposed to waiting for the general availability release. This is a surprise to me. To continue to RC1 I will need to reinstall every program on the machine? This is fairly significant fine print.