If you cannot get windows 8.1 to install updates or any other updates try this:
Go to Control Panel and then type Services in the search area.
Find the Background Intelligence Transfer Service. Right click it and choose Stop.
Find the Windows Update Service. Right click it and choose Stop.
Go to Windows Explorer and then navigate to C:\Windows\SoftwareDistribution folder
Delete everything in the folder. If something won’t delete reboot the PC and then repeat the above.
Now go to the Windows Store from the Start Screen (green icon).
Windows 8.1 should now install.