In Windows 8 or 8.1, the Windows Store may not start: clicking on it very briefly shows the green background but then returns to the desktop or start screen. The Application event log shows the following error (or a similar one):
Running the WsReset.exe also produces an error.
A possible solution is to re-register the Windows Store through Powershell. Run the following from an elevated command prompt:
powershell -ExecutionPolicy Unrestricted Add-AppxPackage -DisableDevelopmentMode -Register $Env:SystemRootWinStoreAppxManifest.xml
This re-registers Windows Store on your computer, allowing you to start it again.
This problem can also exist with PC Settings: see this article for a solution.