VisualStudio with a basic Windows Forms application in C# should be one of the simplest ways.
The default look is not that bad for a business oriented application, and the drag-and-drop features are really simple to learn.
Java Swing with Netbeans graphical editor would be my second choice if you like Java better than C#.
EDIT: From personal experience, I found that styling the application beyond the default look, was simpler in Java Swing, using look-and-feel packages. For Windows Forms (maybe because my lack of experience) I had to do most elements as images in order to get the style I wanted.
The default look is not that bad for a business oriented application, and the drag-and-drop features are really simple to learn.
Java Swing with Netbeans graphical editor would be my second choice if you like Java better than C#.
EDIT: From personal experience, I found that styling the application beyond the default look, was simpler in Java Swing, using look-and-feel packages. For Windows Forms (maybe because my lack of experience) I had to do most elements as images in order to get the style I wanted.