Change the Product Key in Windows 8

It may be the case that changing the product key works only if the system was installed from volume license media. It might not work if the system was installed from OEM or retail media. When changing the product key on a volume license system you must use a Multiple Activation Key (MAK) -- OEM or retail keys will definitely not work.

Volume license media contain a generic volume license product key, so that the system can be installed without entering a product key; after the system is installed, it will automatically contact a Key Management Service server on the corporate network and all will be well -- unless there is no such server.

There are two ways of changing the product key on volume license versions of Windows 8:

• The semi-graphical way:
   
  
  1. Open a console (mouse cursor to lower left corner, right-click, choose Command Prompt), or open the Run dialog box (<Windows><r>, or mouse cursor to lower left corner, right-click, choose Run).
      
  2. Run
     
     slui.exe 3
      
• The command-line way:
   
  
  1. Open a console with elevated privileges, i.e., mouse cursor to lower left corner, right-click, choose Command Prompt (Admin).
      
  2. Run
     
     slmgr.vbs -ipk <product-key>
     
     for example (this is not a valid Multiple Activation Key),
     
     slmgr.vbs -ipk AAAAA-BBBBB-CCCCC-DDDDD-EEEEE
      
  3. Run
     
     slmgr.vbs -ato

I hope this works for you. There is no warranty. Note that by following these instructions you may cause the computer to self destruct, or worse. Proceed at your own risk. Your mileage may vary.