This configuration section cannot be used at this path. This happens when the section is locked at a parent level. Locking is either by default

This configuration section cannot be used at this path. This happens when the section is locked at a parent level. Locking is either by default (overrideModeDefault="Deny"), or set explicitly by a location tag with overrideMode="Deny" or the legacy allowOverride="false".

1) First go to following location
    C:\Windows\System32\inetsrv\config
2) Open the application "applicationHost.config"



Go to<sectionGroup name="system.webServer">
in  this node


Set every section's overrideModeDefault="Allow"


or particular node if you know which on is giving issue


<section name="handlers" overrideModeDefault="Deny" />