ASP.NET application does not work: 0x80070021. This configuration section cannot be used at this path

After reinstalling the Windows, Suite ASP.NET application does not work: 0x80070021. This configuration section cannot be used at this path

Unexpectedly help comes from Microsoft Knowledge Base:

http://support.microsoft.com/kb/942055/

See case #9

http://learn.iis.net/page.aspx/145/how-to-use-locking-in-iis-70-configuration

Editing the %windir%\system32\inetsrv\config\applicationHost.config helped.

Error message:

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 Information

Module	AnonymousAuthenticationModule
Notification	AuthenticateRequest
Handler	PageHandlerFactory-ISAPI-2.0-64
Error Code	0x80070021
Config Error	This configuration section cannot be used at this path. This happens when the section is locked at a parent level. Locking is either by default (overrideModeDefault="Deny"), or set explicitly by a location tag with overrideMode="Deny" or the legacy allowOverride="false".
Config File	\\?\C:\Dev\531Patch00\Root\Web\Logon\web.config