When we create a new C#.Net project (or other .Net project, , the editor includes the following using statements in the code
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms;
But most of this included namespaces are unused, and you don't know which of them you don't need.
So, in Visual Studio 2008 there is a new feature for excluding the unused usings from your project.
In the code editor, click the right mouse button and in the context menu go to Organize Usings -> Remove and Sort

If you have not written additional code, the editor will leave this two using statements
using System; using System.Windows.Forms;








{ 2 comments… read them below or add one }
I have a question here. As part of code clean-up and making code more readable, this makes perfect sense. Let's say you decide to retain all the unused usings and not remove them. Will that be a Performance impact on the app?
Modern day compiler is smart enough to not overload the executable but its always better to control the controllable.