RC candidates beware
Windows 7 does not uninstall automatically. While the installation says it is creating a restore point, that point is not your last operating system as in Vista or Windows XP. Microsoft is not clearly warning people when they download the free release code. None of the support sites contemplate reverting which is too optimistic.
This means if you are not happy with Windows 7 release candidate you can live with it or manually re-install your previous operating system. The last choice is time consuming and complex. All drivers will need to be installed for your computer, all programs, all data.
After 10 days with Windows 7, the bloom is off the rose. Several programs will not work. Most of them are video programs like Adobe Premier Elements, A/V 8, video editing software and video conversion software. The nVidia drivers are beta 1.1 versions.
However, I use those programs daily so I must revert to Vista 64.
I will have to back up all my programs and data. Vista will be re-installed from the Dell OEM disks. The drivers will need to be installed then updated. All the software will be re-installed and the data copied back. It will take 1-2 days.