看一看： http://support.microsoft.com / kb / 306156 / zh-CN [ ^ ]

Take a look: http://support.microsoft.com/kb/306156/en-us[^]

When you debug an ASP.NET application in Visual Studio .NET, you may receive the following error message:
Error while trying to run project: Unable to start debugging on the web server. The project is not configured to be debugged

For ASP.NET projects, verify that you have a valid project file called 'Web.config' for the URL specified and 'debug' is set to 'true' in that file.
For ATL Server projects, verify that the 'DEBUG' verb is associated with your ISAPI extension.
Would you like to disable future attempts to debug ASP.NET pages for this project?

This error can occur primarily because:

    The ASP.NET Application does not have a Web.Config file.
    The Execute Permissions property for the current project folder in Internet Services Manager is set to None.

To resolve this problem, use one of the following methods, depending on your circumstances:

    If your project does not have a Web.config file, add a Web.config file to the directory that contains the ASP.NET application. If you are working in Visual Studio .NET, right-click the project in Project Explorer, click Add New Item, and then click Web Configuration File.
    If your project already has a Web.config file, and if the debug attribute is set to true in the <compilation> section of the Web.config file, follow these steps to set the Execute Permissions property for the project folder:
        Start Internet Services Manager, and then click the project that you are trying to debug.
        Right-click the project, and then click Properties.
        Click the Directory tab.
        If None is selected in the Execute Permissions list, click Scripts only, and then click Apply.

感谢您重播但我已完成所有操作这些想法，直到现在我无法调试我的项目

thank you for replay but i have done all of thi ideas and till now i can not debug my project