I get this note when logged in as host:

Note: You are running on an old version of the .NET Framework. Future upgrades of the DotNetNuke platform will require .NET 3.5 SP1 or later. If you believe you are running .NET 3.5 SP1 already, please check your web.config file and ensure that the 3.5 or above versions of both System.Core and System.Data.Linq are referenced in the assemblies node.

can I see a sample of a correct web.config clean installation for .net 3.5 somewhere?

I have installed 5.2.3 on two different PC's both with 3.5 SP 1 but they both come up with this warning/error message.

My assemblies code in the web.config look like this:-

      <assemblies>
        <add assembly="Microsoft.VisualBasic, Version=8.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A" />
        <add assembly="System.DirectoryServices, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A" />
        <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A" />
        <add assembly="System.Management, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A" />
        <add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" />
        <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
        <add assembly="System.Xml.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" />
        <add assembly="System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" />
        <add assembly="System.Data.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" />
      </assemblies>

 Are the settings incorrect?