You can use Process Monitor to find out which what registry entry controls a particular local group policy setting

• Download Process Monitor.
• Extract files and run Procmon.exe
  
  
• Flick on Filter icon and add following two filters:
• Process Name is mmc.exe then Include
• Operation is RegSetValue then Include
• Now launch Local Group Policy Editor (gpedit.msc) and make the policy change
• Process Monitor will list what registry change(s) were made