I have a virtualbox copy installed with Windows 8 Pro which was activated using free WMC key. I wanna upgrade this to Windows 8.1 version without affecting my license. what would be best possible steps to achieve this. Currently windows update shows total of 3.5gb updates. Windows Store shows me Windows 8.1 Pro update/download but fails to start 3.42gb download and continue. I have also create ISO image using latest prowmc esd file which is9600.17053.winblue_refresh.141120-0031_x64fre_client_professionalwmc_en-us-ir5_cpwmca_x64frer_en-us_esd_728c7a8d4370117b555f0958f6c16d6aef41f6d6.esd. Running setup from this ISO ask for product key.