I am using Flat File Listener.
It does login in "c:\temp\log.txt" when running in Visual studio's web development server.
But nothing is written when hosting it in my local IIS on the same machine.
I have already granted anonymous authentication in IIS.
I am using Visual studio 2008,IIS 5.1 and EntLib 4.1.
Let me know what went wrong.
It sure sounds like permission issues. If you are running your application out of process then the process will be aspnet_wp.exe and the account it runs under will be MACHINENAME\ASPNET.
You should verify that the ASPNET account has write permission to the c:\temp folder. If not, then grant the ASPNET account write access.
If that doesn't work and you still need to troubleshoot, download Process Monitor from sysinternals to see if there are any ACCESS DENIED messages. Although a bit old and using the legacy tool Filemon, (which Process Monitor replaces), this KB article goes through the troubleshooting steps and what to look for.