Converting VS2008 Solution to VS2010 Creates compile errors in ASP.NET 3.5 SP1

I am converting a large solution from Visual Studio 2008 to Visual Studio 2010. The conversion completes without errors. When I go to build the solution one particular section of the application throws error but it didn't when the solution was 2008.

Error 1 Could not load file or assembly 'System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified. C:\MyProject\Results\Result.ascx 3

And

C:\CMyProject\Results\Result.ascx(3): Build (web): Could not load file or assembly 'System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.

The dll is in the bin and it is not in the GAC开发者_如何学Go. The .refresh file is pointing to the correct location. And all sections in the Web.Config are there, if you need to see them let me know.

I have gone over the fixes I found online and nothing seems to help. I would really appreciate if someone could help me or point me in the right direction?

Thank You.

Try to install Microsoft Chart Controls for Microsoft .NET Framework 3.5. You can find it on http://www.microsoft.com/downloads/details.aspx?FamilyID=130f7986-bf49-4fe5-9ca8-910ae6ea442c&DisplayLang=en

That is the charting control, you probably need to get the latest that works with .net 4.0

Some information about it is at: http://msdn.microsoft.com/en-us/library/ee410579(VS.100).aspx