Since the automatic Store update is likely unavailable, the most reliable method is to perform an using an ISO file:
: Before trying the ISO method, ensure your Windows 8 is fully updated through Windows Update in the Control Panel. Specifically, you must have update KB2871389 installed for the 8.1 upgrade to proceed correctly. Can i update windows 8 to 8 1
: Once downloaded, right-click the ISO file and select Mount . This will create a virtual drive in "This PC". Run Setup : Open the new drive and double-click setup.exe . Since the automatic Store update is likely unavailable,