Windows 8.1 Preview version can be unloaded

Windows 8.1 Preview (Preview) can not be unloaded, Microsoft said in the official question and Answer page, the Windows 8.1 Preview version does not support uninstall, you can restore the entire system to the factory state.

If your computer is pre-installed with Windows 8, you can use a computer refresh to restore it to Windows 8. Your personal files will not be affected, but non-computer pre-installed applications will need to be reinstalled, and Windows 8 application stores may no longer provide the applications you installed when using the preview version.

If you are running Windows 8 and you are using this preview version of the ISO installation, you will not be able to uninstall it, you need to reinstall Windows 8 with the restore or installation media that came with your computer. If you do not have recovery media, you can create a USB recovery drive.

If you are running Windows XP, Windows Vista, or Windows 7, you cannot uninstall this preview version. To restore your previous operating system, you need to reinstall from the recovery or installation media (usually DVD media) that came with your computer. If you do not recover the media, you can use the computer manufacturer's software to create the recovery media by using the computer's recovery partition prior to the update. After you install the Windows 8.1 Preview, you will not be able to use the recovery partition on your computer to restore the previous version of Windows.

If you are currently using Windows RT, you will not be able to uninstall the Windows RT 8.1 Preview version. Upgrade to the official version of Windows RT 8.1 only when the final official version is launched.