Microsoft.Office.Interop.Word namespace overriding my System namespace? C# ASP.net
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I am trying to fix this legacy app that was created using Visual Studio 2003, using Microsoft Office Interops version 11, .NET 2.0.  I am trying to fix it in Visual Studio Express 2010 to reference Interops version 14, .NET 4.0 -- as noted in my previous question on StackOverflow, the legacy app works fine in Windows 7 but after I close it, the Microsoft Office products are crashing when I try to use them.

However, when I fix the references in VS2010 (delete old v.11 Interops, add in new v.14 Interops) and then attempt to publish the application, I get errors like

    'Microsoft.Office.Interop.Word.System does not contain a definition for IO'

It looks like VS2010 does not see my System namespace being used when the Word namespace is referenced?  When I removed the 

    using Microsoft.Office.Interop.Word

namespace and then try to publish, the errors like the above disappear and I only get the expected errors related to the missing Word reference like

    The type or namespace name '_Document' could not be found (are you missing a using directive or an assembly reference?)

I already included the System.dll in the reference so I'm not sure what's going on?  Thanks for reading!