Error While Running Debugger in Visual Studio 2005

Error    1    It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. 

This error can be caused by a virtual directory not being configured as an application in IIS.       

I was working with Visual Studio .NET 2005 and opened a local copy of a .NET web site that I had saved and received the above error.

Unlike what you might think, your IIS virtual directory not being configured as an application is not the problem.  The problem lies in the web.config file that was created in a folder named "Backup" within your project when you converted or someone converted your old .NET 2003 .sln and .proj project files to .NET 2005.  

How do you solve the  MachineToApplication compile error? 

 Simply move your Backup folder into a directory above your project folder and rebuild your project.