Q:

Not debug in visual studio 2008

I'm reporting this error when I try to execute in debug the application:

The application you are trying to debug uses a version of the Microsoft .NET Framework that is not supported by the debugger. 
The debugger has made an incorrect assumption about the Microsoft .NET Framework version your application is going to use. 
The Microsoft .NET Framework version specified by you for debugging is incorrect.

I'm using Visual Studio 2008 and .NET Framework 3.5.
I've got this problem with a particular project. Another project with the same framework and visual studio version works perfectly.
This suggests me that this is a problem of the project. 
Any idea of why? Which property to set?
Thank you very much

A:

Check to ensure that the application pool you are running the site under is set for the correct .Net runtime version. In IIS you can set that up in IIS Manager site configuration. With IISExpress you just need to modify the applicationhost.config file to set the site to use the correct app pool, or configure the app pool to use the proper version.

