From an elevated (right click 'runas as admin') powershell prompt
$apps = Get-ChildItem "C:\Program Files\WindowsApps"
Foreach($app in $apps)
{
Add-AppxPackages -Path "$($app.FullName)\AppxManifest.xml" -Register -DisableDevelopmentMode 2> Out-Null
}
$apps = Get-ChildItem "C:\Windows\SystemApps"
Foreach($app in $apps)
{
Add-AppxPackages -Path "$($app.FullName)\AppxManifest.xml" -Register -DisableDevelopmentMode 2> Out-Null
}