How to download the official Microsoft Windows 8.1 ISO

Step 1: Go to Microsoft's page for upgrading to Windows 8 with a product key, then click on the light blue "Install Windows 8" button.
Step 2: Launch the setup file (Windows8-Setup.exe) and enter your Windows 8 product key when prompted. Continue the setup process until it begins downloading Windows 8.
Step 3: Close the Windows 8 setup window and confirm that you want to quit the setup.
Step 4: Back at the Microsoft upgrading to Windows 8 with a product key page, click on the light blue "Install Windows 8.1" button this time.
Step 5: Launch the setup file (WindowsSetupBox.exe), which will begin downloading the Windows 8.1 ISO.
Step 6: Once the ISO finishes downloading, the installer will take several minutes to check the download and uncompress the install files. When you're prompted to choose an installation option, pick "Install by creating media."
Step 7: Decide whether you want the installer to create USB flash drive media, or save the ISO file.
If you choose ISO, the ISO file (Windows.iso) will be saved to your PC and you'll be given the option to burn it to DVD. Once completed, you can actually go back and create the USB flash drive media as well. Just click on the "Install Windows" link on your Windows desktop. You'll be prompted to choose your installation option again. Pick "Install by creating media" again, insert a 4GB or larger USB flash drive, then choose the USB flash drive option. If you have any problems creating the USB flash media, you can still use the Windows 7 USB/DVD download tool to create USB media with the Windows 8.1 ISO.

®  Repair Windows 8.1 update from Windows 8 with USB Repair stick  ®

I've got a OEM DVD. With which it is not possible to download a Windows 8 or 8.1 ISO, and...
with my Windows 8 OEM DVD it is also not possible to carry out a repair, using the DVD and place back a WindowsImageBackup.

I found out after several exercises to use the Repair in the Configuration section: "Recovery Media Creator" gives at least the possbility to repair Windows 8.1 without the DVD.

After updating from Windows 8 to Windows 8.1, a repair with the Windows 8 DVD appears not to be possible, but is possible with the Windows USB Stick as follows:
♥ Make an image from the Windows 8.1 system with the Windows possibility using the Command Prompt (administrator) and the command:   wbadmin start backup -backupTarget:X: -include:C: -allCritical –quiet, where X is the drive to place the image (WindowsImageBackup), e.g. replace X with D or E.
♥ Make a Repair-stick using the Repair procedure given by the Configuration possibility in Windows.
Than:
♥ Make sure the WindowsImageBackup file, to be used is placed in the root of one of the internal computer drives.
♥ Place the USB-stick in a USB port and make it the first Start-up option in the BIOS.
♥ After starting up choose your own Keyboard selection.
♥ Than click on “Solving Problems”
♥ Than for “Advanced options”
♥ After that “Repair with installation-copy”
♥ Click on the Windows 8.1 icon
♥ Than the program will look for the WindowsImageBackup file in the root of a drive / partition  (D: or E: or…)
♥ If found click on “Next” in the window “Replace a systemcopy on the computer – Select a systemcopyback-up”
♥ Click on “Next” and in the following window on “Complete”
♥ After that click “Yes” in the warning window after which the system starts running and placing back the image!
♥ Make sure that in the BIOS the subject HDD or SSD goes before the USB-stick option and…

Microsoft allow us 90 days free trial for x86 and 64bit from microsoft official website from below link.

http://go.microsoft.com/fwlink/?LinkId=302161   (64 bit)


http://go.microsoft.com/fwlink/?LinkId=302162   (32 bit)