After moving from Windows 8 to 8.1 you may see that Windows Store no longer works.
To fix this, use this path:
1. Run CMD or powershell as an administrator
2. Enter this in cmd: powershell -ExecutionPolicy Unrestricted Add-AppxPackage -DisableDevelopmentMode -Register $Env:SystemRoot\WinStore\AppxManifest.xml
3. Type: start "" "ms-windows-store:"
To fix this, use this path:
1. Run CMD or powershell as an administrator
2. Enter this in cmd: powershell -ExecutionPolicy Unrestricted Add-AppxPackage -DisableDevelopmentMode -Register $Env:SystemRoot\WinStore\AppxManifest.xml
3. Type: start "" "ms-windows-store:"