Also note that the final release of Windows 8 will not support upgrading from any prior Windows 8 "Preview" release, though the migrate option will still be supported.
Microsoft does not recommend upgrading from a beta, and may actively prevent it. Windows RTM should always be clean installed which means preferred applications and utilities have to be clean installed too.
While it is possible to transfer your personal files from Windows 8 Consumer Preview to Windows 8 Release Preview using Windows Easy Transfer, we do not recommend using Windows Easy Transfer to also move your settings. If you do chose to use Windows Easy Transfer to transfer your personal files, it is very important that you follow these steps precisely so that you do NOT also transfer any Windows settings or apps settings. It should also be noted that Windows Easy Transfer will not move your apps – they will need to be reinstalled after installing Windows 8 Release Preview.