Firstly accepting that you would not normally be running IIS on Windows 10 other than for dev work… today I was unable to get past errors where I could not browse even to the iisstart.htm page:
That manifested itself as Event Ids 1500 and 1511 in the Event logs:
Windows cannot log you on because your profile cannot be loaded. Check that you are connected to the network, and that your network is functioning correctly.
DETAIL – Access is denied.
Windows cannot find the local profile and is logging you on with a temporary profile. Changes you make to this profile will be lost when you log off.
My final attempt was to browse through the app pool defaults and in desperation switch off the “Load User Profile” setting.
And that worked: