Hi,
When you change SharePoint Diagnostic Logging to use verbose, the log files will growth rapidly, so you should only use verbose mode for short periods of time.
If you change a lot of the default settings, since each category is set to a specific level (let’s say, for Backup category levels “Error” and “medium”, while maybe Search was at “Information” and “Verbose”) and want to restore everything backup to default the best way is using the STSADM command STSADM.EXE -o setlogginglevel -default
But if you have enough patience and you know exactly the levels for all categories, you can of course do it using the UI 😉
