I am thinking about getting a pre-order for Windows 7 upgrade, but I don't want to buy it if I can't do clean installs with it. How does the upgrade process work exactly when comming from Windows Xp or Vista? I've poked around on Google, but I have only been able to find documentation regarding the Windows 7 RC to RTM migration.
Would I have to install Windows Xp or Vista first every time I wish to format and reinstall Windows 7 on my computer? Or would I just have to, for example, punch in my old Xp/Vista product key?