This tip is for Windows SharePoint Services 3.0 and Microsoft Office SharePoint Server 2007 and may apply to SharePoint Foundation 2010 and SharePoint Server 2010.
One great way to troubleshoot any SharePoint issue is to set the SharePoint diagnostics logging to “Verbose” for the category which fits with the technology that having an issue. There is an “All” category, but that is usually too much information, so it's best to set logging on different categories. After troubleshooting has been completed how can you get back to the normal logging setting so the logging not impacting performance or logging too much noise? Here is the Stsadm.exe command to set the logging levels back to defaults.
Stsadm.exe -o setlogginglevel -default
There you go, back to normal.
Note that this is farm-wide, so just run once on any SharePoint server in the farm. Note that this will not set the location or the number of log files or minutes to log in each file, we’ll leave that for another tip. :)
For SharePoint 2010 and 2013 use PowerShell Clear-SPLogLevel.