ASP NET C# System.Windows.Form does not exist in the class or namespace 'System'

ASP NET C# using System.Windows.Form namespace producce error开发者_开发百科 "The type or namespace name 'Windows' does not exist in the class or namespace 'System' (are you missing an assembly reference?)".

I test it with WinXP ver 2002 SP3, MS Visual Studio Microsoft Development Enviroment 2002 ver 7, framework 2.0; and with Win7Professional, MS Visual Studio 2008 Express, framework 3.5 (inside Win7?)

Add a reference to System.Windows.Forms in the visual studio by right-clicking the references or project in the solution explorer.

But I could not figure out what it has got to do with ASP.NET?

Are you trying to create web or desktop application? You can't use both within a single project.
If you want to create a new desktop application, you can do it by selecting:

File -> New -> Project -> Visual C# -> Windows - Windows Forms Application