Go to: start --> run --> inetmgr
Expand your website and locate the folder the contains your .NET project right click and choose properties. Where is says application click 'Create' and the directoy will be setup as an application. This should fix your problem.
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Read this if you want to know how to get a correct reply for your question:
http://www.catb.org/~esr/faqs/smart-questions.html
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Technical Editor for:
Professional Search Engine Optimization with ASP.NET
Professional IIS 7 and ASP.NET Integrated Programming
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