Microsoft today confirmed that they will be releasing Windows 8.1 preview on June 26th during BUILD conference. If you are planning to upgrade from your current Windows 8 to Windows 8.1 preview, you need to be careful. Because, you will have to re-install all the apps you have installed on your PC after upgrading Windows 8.1 to final version which will be released later this year. When the Windows 8.1 preview is made available, Windows 8 and Windows RT users will receive a Windows Update notification. Users can go to Windows Store, read the description and choose whether to install or not. Here is the procedure from upgrading from Windows 8.1 to Windows 8.1 RTM,
Even if testers opt instead to roll their devices back to Windows 8 after installing the preview bits, they still will have to reinstall their apps once they move to the RTM version of Windows 8.1.
On Windows RT devices, it’s the Windows Store/Metro-Style apps that will have to be reinstalled; for x86-based Windows 8 systems, testers will need to reinstall both their Windows Store/Metro-Style and Desktop apps, a Microsoft spokesperson said.
Read more about it from the link below.