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Microsoft is all set to release the first Preview version of Windows 8.1 update and most Windows users are eagerly waiting for this update even since some leaked builds revealed that this update isn't a service pack and instead, includes hundreds of new features as well as enhancements.
As some of you know, Windows 8.1 update is completely free for all existing Windows 8 users. That is, users who're running Windows 8 can upgrade to 8.1 with ease for free, as 8.1 will be available as an update from the official Windows Store in Windows 8. Users who're running Windows 7 and Vista can also explore the new features in Windows 8.1 by downloading Windows 8.1 ISO file and then installing Windows 8.1 in dual boot with Windows 7/Vista.
But before you upgrade Windows 8 to Windows 8.1 Preview, there are a couple of things that you need to know.
Disk space requirement: If you plan to upgrade your existing Windows 8 installation to Windows 8.1 Preview, make sure that you have at least 4 GB of free disk space on your Windows 8 drive before hitting the upgrade button. And if you plan to perform a clean installation, then Microsoft recommends at least 16 GB free space for x86 and 20 GB for x64.
Upgrade from Windows 8.1 Preview to 8.1 RTM possible, but with a catch: Even though it's possible to upgrade from Windows 8.1 Preview build to the final one (RTM), you'll need to uninstall all installed apps and desktop programs while upgrading to the RTM. In other words, you will need to reinstall all installed apps and desktop programs once you upgrade to Windows 8.1 RTM.
Windows 8.1 is also available as an ISO file: To help all Windows 8 users who would like to test drive the 8.1 update without actually updating their existing Windows 8 installations to the 8.1 Preview, Microsoft is offering Windows 8.1 Preview as an ISO file as well(see how to install Windows 8 from ISO file). This will also help Windows 7, Vista, and Mac users test 8.1 Preview on their machines.
Uninstallation isn't possible: Even though Windows 8.1 Preview is available as an update from Windows Store to current Windows 8 users, it seems that you can't uninstall or remove 8.1 update or downgrade Windows 8.1 Preview to Windows 8. So, if you're on Windows 8 and want to explore Windows 8.1, we suggest you either dual boot Windows 8 with Windows 8.1 or install Windows 8.1 in a virtual machine such as VirtualBox or VMware Player.
Windows 8.1 RTM release date: While Microsoft is yet to reveal the official release date of Windows 8.1 RTM, Windows 8.1 RTM will be available to OEMs, MSDN and TechNet users towards the end of August or in the first half of September. Windows 8.1 RTM public release likely to happen in October, 2013. That is, once you upgrade your Windows 8 to Windows 8.1 Preview, you'll need to live with Windows 8.1 Preview for the next couple of months.
