Specifies the Start screen layout for users.This setting lets you specify the Start screen layout for users and prevents them from changing its configuration. The Start screen layout you specify must be stored in an XML file that was generated by the Export-StartLayout PowerShell cmdlet.To use this setting you must first manually configure a device's Start screen layout to the desired look and feel. Once you are done run the Export-StartLayout PowerShell cmdlet on that same device. The cmdlet will generate an XML file representing the layout you configured.Once the XML file is generated and moved to the desired file path type the fully qualified path and name of the XML file. You can type a local path such as C:\StartLayouts\myLayout.xml or a UNC path such as \\Server\Share\Layout.xml. If the specified file is not available when the user logs on the layout won't be changed. Users cannot customize their Start screen while this setting is enabled.If you disable this setting or do not configure it the Start screen layout won't be changed and users will be able to customize it.
Start Menu and Taskbar
At least Windows Server 2012 R2 Windows 8.1 or Windows RT 8.1
HKCU\Software\Policies\Microsoft\Windows\Explorer!LockedStartLayout; HKCU\Software\Policies\Microsoft\Windows\Explorer HKCU\Software\Policies\Microsoft\Windows\Explorer!StartLayoutFile