What should I do if my IIS is corrupted in Vista? Should I do a windows repair or re-install the whole operating system?

What is the exact error message that you receive? What are you doing when the error message occurs?

Well, you see I'm doing a ASP.NET Webpage right now in Visual Studio 2008, and I couldn't view it in browser. And also I never got this message before. Here is the message:

Server Error in '/Practice0' Application.
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Configuration Error
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS.

Source Error:


Line 84: ASP.NET to identify an incoming user.
Line 85: -->
Line 86: <authentication mode="Windows" />
Line 87: <!--
Line 88: The <customErrors> section enables configuration


Source File: C:\Users\Richard Chow\Desktop\Practice\Practice0\webmanagement\web.config Line: 86


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Version Information: Microsoft .NET Framework Version:2.0.50727.1433; ASP.NET Version:2.0.50727.1433

That's way outta my league! Just a guess, but I'd say there was an error in Line 86: Line 86: <authentication mode="Windows" />
I'd suggest posting over in the Programming forum: http://www.bleepingcomputer.com/forums/forum26.html
or the Web Site Development forum: http://www.bleepingcomputer.com/forums/forum38.html

Thanks, but I got the problem solved. The problem was that web.config file is not supposed to be in the same folder with my ASP.NET Webpages.

Thanks for letting us know! I've gotta get around to learning how to program one of these days!

No, thank you for all of your help. I appreciate it.