IIS application host config changes detection

1. I want observe any changes made to IIS applicationHost.config .I know i can use file system watcher to watch changes made to host config file . But how to detect the applicationhost.config file location in c#.

2. Is there any API to notify the changes made in applciaitonsost.config

3. I know application host config reside in %WINDIR%\System32\inetsrv\config . but is this default location for all windows environment and Is it changeable ?

Thanks.