Missing Remote Installation Services in GPO editor
You can delete it manually from the GPO:
Go to C:\Windows\SYSVOL\domain\Policies\{31B2F340-016D-11D2-945F-00C04FB984F9}\USER\Microsoft (the GUID is the same on all systems, it is the Default Domain Policy) and delete the folder Remote Installation. Refresh your GPO settings editor afterwards and RIS will be gone.