Default IIS logfile locations

c:\inetpub\logs\LogFiles
C:\Windows\System32\LogFiles\ for a variety of errors

 

If you don’t find it, it isn’t installed. You need to fire up Programs and Features then click on Turn Windows features on or off on the left side then select Internet Information Services\World Wide Web Services\Health and Diagnostics\HTTP Logging per a comment on Where can I find the IIS logs?

 

 

 

Log4Net

See Windows.Logging for more details
It’s my go-to Windows logging tool -- desktop and web.

 

 

See Also

Troubleshooting
Debugging