HTTP Error 500.19 - Internal Server Error for silverlight application

Use VS2010 silverlight business application template to createa defaut solution. Change authentication to Windows in Web.config and the code in app.xaml.cs to use wind开发者_C百科ows authentication. Nothing else changed. Then run this app from vs2010 built-in web server, it is fine, I can see the login user info from windws(from a AD domain account) display on the top-right of the screen, like DomainName\userName.

Then deploy this web app to IIS on windows 7(same computer) and access this app again, I got following error:

HTTP Error 500.19 - Internal Server Error
The requested page cannot be accessed because the related configuration data for the page is invalid.

Detailed Error InformationModule IIS Web Core
Notification Unknown
Handler Not yet determined
Error Code 0x80070005
Config Error Cannot read configuration file due to insufficient permissions 
Config File \\?\C:\Users\myname\Documents\Visual Studio 2010\Projects\BusinessApplication4\BusinessApplication4.Web\web.config
Requested URL http://localhost:77/BusinessApplication4TestPage.html
Physical Path 
Logon Method Not yet determined
Logon User Not yet determined
 Config Source
   -1:
    0:

how to resolve this problem?