Go to
Ctrl X
Bring up the Windows powershell admin
Type in the following
powershell -ExecutionPolicy Unrestricted Add-AppxPackage -DisableDevelopmentMode -Register $Env:SystemRoot\WinStore\AppxManifest.xml
Go back to windows store and it should re-work!!
Kudos to Luis Cantero from this post http://answers.microsoft.com/en-us/windows/forum/windows8\_1-windows\_store/just-updated-to-windows-81-and-the-windows-store/c4cf204d-bd99-426c-b800-9c9125ae739c?page=2
Enjoy
Yahya Al-Din