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):

Event log
Activation of app winstore_cw5n1h2txyewy!Windows.Store failed with error: This app does not support the contract specified or is not installed. See the Microsoft-Windows-TWinUI/Operational log for additional information.

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-AppxPa  ...