I am running IIS 7.5 on Windows Server 2008 R2 x64. I added a new app pool via the iis manager and wanted to set the autostart and startmode options in the applicationHost.config file. However, the new app pool is not appearing in either of the applicationHost config files (%WINDIR%\System32\inetsrv\Config and %WINDIR%\SysWOW64\inetsrv\config). The app pool has an application added to it (the application is still listed under the old app pool in the config files, though it is correct in the iis management snap-in). I have run iisreset several times and completely restarted the server.
Does anyone know if these config files are cached somewhere else that may not be refreshing or anything else that may cause this behavior?
I'm not sure why this would occur, but I accessed the applicationHost.config from another machine via the admin share and the information was there and editable.
I opened the file using notepad++ with "Run as Administrator". I spent nearly an hour trying to figure out what was going on. I just couldn't see the binding. Turns out, the only way to edit applicationHost.config is to start Notepad (not notepad++) using "Run as Administrator" and open the file. Only then you will see the actual content of the file.
来源：https://stackoverflow.com/questions/7637268/iis-7-5-app-pool-not-in-applicationhost-config