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

Question

I am getting Unrecognized configuration section system.web/protocols error. What might be the reason?. Is identity impresonate is not allowed inside system.web tag..?? Please see my web.config file below for more details.
<system.web>
<identity impersonate="true" userName="admin" password="adminpwd"/>
<pages>
<controls>
<add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" namespace="System.Web.UI" tagPrefix="asp"/>
</controls>
</pages>
<compilation debug="true" strict="false" explicit="false">
<assemblies>
<add assembly="Microsoft.Practices.EnterpriseLibrary.Common, Version=3.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
<add assembly="System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
</assemblies>
</compilation>
<httpHandlers>
<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
<add verb="GET" path="CrystalImageHandler.aspx" type="CrystalDecisions.Web.CrystalImageHandler, CrystalDecisions.Web, Version=10.2.3600.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
</httpHandlers>
<httpModules>
<add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</httpModules>
<authentication mode="Windows"/>
<sessionState cookieless="false" timeout="120"/>
<customErrors mode="Off"/>
<httpRuntime executionTimeout="1500" maxRequestLength="80000" requestLengthDiskThreshold="80000" useFullyQualifiedRedirectUrl="false" minFreeThreads="8" minLocalRequestFreeThreads="4" appRequestQueueLimit="5000" enableKernelOutputCache="true" enableVersionHeader="true" requireRootedSaveAsPath="true" enable="true" shutdownTimeout="90" delayNotificationTimeout="5" waitChangeNotification="0" maxWaitChangeNotification="0" enableHeaderChecking="true" sendCacheControlHeader="true" apartmentThreading="false"/>
</system.web>
This is the error message
Error 102 Unrecognized configuration section system.web/protocols. (C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Config\web.config line 297)
Also the error ocurred when i copied the source code from another machine.

Answer 1

Problem fixed.I have looked at c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Config\web.config and NOT the project web.config file and only removed the protocols tag which was empty (I really don't understand why!!!) I have not added any single line to the project Web.config file. I hope this will help anyone there having the same problem.