Migrate nested website from IIS6 to IIS7.5 : There is a duplicate 'system.web.extensions/scripting/scriptResourceHandler' section defined

Hello all,

I'm trying to migrate two nested websites to a Windows Server 2008, IIS7.5. They initially were on a Windows Server 2003, IIS6.

IIS
-- FirstWebsite (.NET2.0)
----SecondWebsite (.NET3.5)

They are both on their own application pools, Framework 2.0 Integrated.

No problem with FirstWebsite. But when I tried to display SecondWebsite, I have the following error :

HTTP Error 500.19 - Internal Server Error
Config Error There is a duplicate 'system.web.extensions/scripting/scriptResourceHandler' section defined

7:         <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>

During my google research, I tried several modifications, like change the application pools configurations to Classic mode, check their framework versions, ... No result.

I suppose SecondWebsite inherit of FirstWebsite configuration. I tried to comment these lines in the SecondWebsite's web.config, but the versions of the assemblies are different, so it could have consequences on this website.

I didn't configure the old website, on the 2003 server and IIS6. I can't figure out why it works perfectly on this one and not on the 2008.

Does anybody have an idea ? Tell me if you need any other information.

Thanks for your help.