Hello sir HTTP Error 500.23 - Internal Server Error An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode.
This application defines configuration in the system.web/httpHandlers section. From
MAnoj
Are you using IIS 7?
If yes, Try the solution given in the following link.
http://mvolo.com/blogs/serverside/archive/2007/12/08/IIS-7.0-Breaking-Changes-ASP.NET-2.0-applications-Integrated-mode.aspx