Do you know that Microsoft has launched The Windows 8.1 Release Preview ? The Usersneed have full fill your this need and The Windows 8.1 is available for you to download , install and online setup for Windows 8.1 this version of windows is latest version of Microsoft Operating Systems.Windows 8.1 can be upgraded on WIndows 8, 7 and XP ( But for XP You should have to Download and InstallWindows XP Service Pack 3 then upgrade Windows XP to Windows 8.1). You can roll back your upgraded Window 8.1 also with the previous version of windows.
Widows 8.1 is available in ISO format and EXE file which is for online download and install. Windows 8.1 Release Preview ISO files (.iso) are provided as an alternative to using Windows 8.1 Release Preview Setup. If you are on a PC running Windows and want to install the release preview on another partition, another PC, or a virtual machine, we recommend you download Windows 8.1 Release Preview Setup and use the built-in tools for converting an ISO image into installation media, such as a DVD or USB bootable flash drive.
Note: Before you download: Windows 8.1 Release Preview is prerelease software that may be substantially modified before it’s commercially released. Microsoft makes no warranties, express or implied, with respect to the information provided here. Some product features and functionality may require additional hardware or software.
How to Install Windows 8: The easiest way to convert an ISO file to a DVD in Windows 7 is to use Windows Disc Image Burner. On a PC running Windows XP or Windows Vista, a third-party program is required to convert an ISO file into installable media—and DVD burning software often includes this capability. One option is the USB/DVD download tool provided by the Microsoft Store. You can also download Windows 8.1 Release Preview Setup, which includes tools that allow you to create a DVD or USB flash drive from an ISO file (Windows Vista or Windows 7 required).
Important: If you decide to go back to your previous operating system, you'll need to reinstall it from the recovery or installation media that came with your PC, which is typically DVD media. If you don’t have recovery media, you might be able to create it from a recovery partition on your PC using software provided by your PC manufacturer. Check the support section of your PC manufacturer’s website for more information. After you install Windows 8.1, you won’t be able to use the recovery partition on your PC to go back to your previous version of Windows. 
Requirements:
Processor: 1 gigahertz (GHz) or faster
RAM: 1 gigabyte (GB) (32-bit) or 2 GB (64-bit)
Hard disk space: 16 GB (32-bit) or 20 GB (64-bit)
Graphics card: Microsoft DirectX 9 graphics device with WDDM driver
Additional requirements to use certain features:
To use touch, you need a tablet or a monitor that supports multitouch.
To access the Windows Store and to download and run apps, you need an active Internet connection and a screen resolution of at least 1024 x 768.
To snap apps, you need a screen resolution of at least 1366 x 768.
Internet access (ISP fees might apply)
Product Key:
NTTX3-RV7VB-T7X7F-WQYYY-9Y92F
Download Windows 8.1 32 Bit and 64 Bit
