title: When I work with SqlConnection in C# i get en Error
body: <p>i try to work with SqlConnection in C# (VS2008) , and i get this error:</p>
  
  <p>The type 'System.Data.SqlClient.SqlConnection' exists in both 'c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Data.dll' and 'c:\Program Files\Microsoft Visual Studio 8\Common7\IDE\PublicAssemblies\System.Data.SqlClient.dll'   D:\test\DBDB\DBDB\Form1.cs  15  9   DBDB</p>
  
  <p>what it can be ?</p>