Windows 7

Probably the last version of Windows as we know it. Interestingly enough, it seems to have a workaround that allows you to do a clean install from an upgrade disk (something I’m noting down here because it is sure to be very useful in the future to create new VMs):

1. Perform a clean installation using the Upgrade disc
2. Make sure there are no Windows Updates pending — if there’s an orange shield icon next to the Shutdown button in the Start Menu, that means you need to reboot before attempting the next steps.
3. Open regedit.exe from the Start Menu
4. Navigate to HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/CurrentVersion/Setup/OOBE/
5. Change MediaBootInstall from 1 to 0
6. Run cmd.exe with Ctrl+shift+enter to run it as an elevated-permissions user
7. Type slmgr /rearm to reboot and run the Activate Windows utility

Also, there seems to be something called the Windows 7 USB/DVD Download Tool, available someplace here to do the obvious and help build a bootable USB drive from a DVD.