Unrecognized configuration section system.web/configuration - asp.net

Question

i'm getting this "Unrecognized configuration section system.web/configuration when i set my admin,staff and user authentication .please help me with this.by here i provide the web.config code
<?xml version="1.0"?>
<!--
Note: As an alternative to hand editing this file you can use the
web admin tool to configure settings for your application. Use
the Website->Asp.Net Configuration option in Visual Studio.
A full list of settings and comments can be found in
machine.config.comments usually located in
\Windows\Microsoft.Net\Framework\v2.x\Config
-->
<configuration>
<appSettings/>
<connectionStrings>
<add name="ConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\ASPNETDB.MDF;Integrated Security=True;User Instance=True" providerName="System.Data.SqlClient"/>
<add name="ASPNETDBConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Se7en\Desktop\Personal\VIVA\1\App_Data\ASPNETDB.MDF;Integrated Security=True;Connect Timeout=30;User Instance=True" providerName="System.Data.SqlClient"/>
</connectionStrings>
<system.web>
<!--
Set compilation debug="true" to insert debugging
symbols into the compiled page. Because this
affects performance, set this value to true only
during development.
Visual Basic options:
Set strict="true" to disallow all data type conversions
where data loss can occur.
Set explicit="true" to force declaration of all variables.
-->
<configuration>
<system.web>
<authentication mode="Forms">
<forms loginUrl="Login.aspx">
<credentials passwordFormat="Clear">
<user name="admin" password="password"/>
</credentials>
</forms>
</authentication>
<authorization>
<allow users="*"/>
</authorization>
<compilation debug="true"/>
</system.web>
<location path="adminstrator">
<system.web>
<authorization>
<allow users="adminstrator"/>
<deny users="*"/>
</authorization>
</system.web>
</location>
<location path="staff">
<system.web>
<authorization>
<allow users="staff"/>
<deny users="*"/>
<allow roles="adminstrator" />
</authorization>
</system.web>
</location>
<location path="user">
<system.web>
<authorization>
<deny users="?"/>
</authorization>
</system.web>
</location>
</configuration>
<!--
<authentication mode="Forms"/>
-->
<roleManager enabled="true"/>
<compilation debug="true" strict="false" explicit="true" targetFramework="4.0">
<assemblies>
<add assembly="System.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/></assemblies></compilation>
<pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID">
<namespaces>
<clear/>
<add namespace="System"/>
<add namespace="System.Collections"/>
<add namespace="System.Collections.Generic"/>
<add namespace="System.Collections.Specialized"/>
<add namespace="System.Configuration"/>
<add namespace="System.Text"/>
<add namespace="System.Text.RegularExpressions"/>
<add namespace="System.Linq"/>
<add namespace="System.Xml.Linq"/>
<add namespace="System.Web"/>
<add namespace="System.Web.Caching"/>
<add namespace="System.Web.SessionState"/>
<add namespace="System.Web.Security"/>
<add namespace="System.Web.Profile"/>
<add namespace="System.Web.UI"/>
<add namespace="System.Web.UI.WebControls"/>
<add namespace="System.Web.UI.WebControls.WebParts"/>
<add namespace="System.Web.UI.HtmlControls"/>
</namespaces>
</pages>
<!--
The <authentication> section enables configuration
of the security authentication mode used by
ASP.NET to identify an incoming user.
-->
<!--
The <customErrors> section enables configuration
of what to do if/when an unhandled error occurs
during the execution of a request. Specifically,
it enables developers to configure html error pages
to be displayed in place of a error stack trace.
<customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
<error statusCode="403" redirect="NoAccess.htm" />
<error statusCode="404" redirect="FileNotFound.htm" />
</customErrors>
-->
</system.web>
<!--
The system.webServer section is required for running ASP.NET AJAX under Internet
Information Services 7.0. It is not necessary for previous version of IIS.
-->
</configuration>

Answer 1

Try this:
<configuration>
<appSettings/>
<connectionStrings>
<add name="ConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\ASPNETDB.MDF;Integrated Security=True;User Instance=True" providerName="System.Data.SqlClient"/>
<add name="ASPNETDBConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Se7en\Desktop\Personal\VIVA\1\App_Data\ASPNETDB.MDF;Integrated Security=True;Connect Timeout=30;User Instance=True" providerName="System.Data.SqlClient"/>
</connectionStrings>
<location path="adminstrator">
<system.web>
<authorization>
<allow users="adminstrator"/>
<deny users="*"/>
</authorization>
</system.web>
</location>
<location path="staff">
<system.web>
<authorization>
<allow users="staff"/>
<deny users="*"/>
<allow roles="adminstrator" />
</authorization>
</system.web>
</location>
<location path="user">
<system.web>
<authorization>
<deny users="?"/>
</authorization>
</system.web>
</location>
<system.web>
<roleManager enabled="true"/>
<compilation debug="true" strict="false" explicit="true" targetFramework="4.0">
<assemblies>
<add assembly="System.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
</assemblies>
</compilation>
<pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID">
<namespaces>
<clear/>
<add namespace="System"/>
<add namespace="System.Collections"/>
<add namespace="System.Collections.Generic"/>
<add namespace="System.Collections.Specialized"/>
<add namespace="System.Configuration"/>
<add namespace="System.Text"/>
<add namespace="System.Text.RegularExpressions"/>
<add namespace="System.Linq"/>
<add namespace="System.Xml.Linq"/>
<add namespace="System.Web"/>
<add namespace="System.Web.Caching"/>
<add namespace="System.Web.SessionState"/>
<add namespace="System.Web.Security"/>
<add namespace="System.Web.Profile"/>
<add namespace="System.Web.UI"/>
<add namespace="System.Web.UI.WebControls"/>
<add namespace="System.Web.UI.WebControls.WebParts"/>
<add namespace="System.Web.UI.HtmlControls"/>
</namespaces>
</pages>
<!--
The <authentication> section enables configuration
of the security authentication mode used by
ASP.NET to identify an incoming user.
-->
<authentication mode="Forms">
<forms loginUrl="Login.aspx">
<credentials passwordFormat="Clear">
<user name="admin" password="password"/>
</credentials>
</forms>
</authentication>
<!--
The <customErrors> section enables configuration
of what to do if/when an unhandled error occurs
during the execution of a request. Specifically,
it enables developers to configure html error pages
to be displayed in place of a error stack trace.
<customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
<error statusCode="403" redirect="NoAccess.htm" />
<error statusCode="404" redirect="FileNotFound.htm" />
</customErrors>
-->
</system.web>
</configuration>