This solution by david worked for me:
Give this a try.................................
Right click at Start button > select Command Prompt (Admin) > type powershell > press Enter > wait a bit until you see....
PS C:\windows\system32>
At the flashing prompt, copy and paste this( please use Copy and paste to avoid typo) ............
Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}
> press Enter.
Ignore any error in red.
When finished, try Start button again.
davidhk129, Oct 17, 2015
#7