I once enable the default filed in IIS Logging.
But the after I need to change and add other fields for Logging.
How to full Disabled Logging in IIS and Then after How to set as a new.
Do you mean you want to let the IIS add the logs as with the new fields setting for the previous logs?
In my opinion, this is impossible. The IIS logs will just log for the new field after you modified the fields. It will not keep the previous logs fields value.