Access to path denied in FileUpload

I have Vista Sp1 and Visual Studio 2008 pro. I'm debugging my first asp.net aplication on local computer. When I try to apply SaveAs() to FileUpload I have "Access denied to path...." exception. My filename alright, my Server.MapPath() alright. What to do? I'm disabled and much depend on this job. Please, help me. Would be I am to set up on my local computer some special features? I did not work for 10 years and far behind current technologies. Besides I don't know much how to manage Vista.

Thanks in advance,

Sergey.
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