What part of the toolbox used?

[dday9]

By rectangle, I assume that you mean a panel. A panel is a container, and is used primarily to hold a collection of controls. It's found under Toolbox -> Containers -> Panel. As for the 15 smaller squares, you could again use a panel, a picturebox, or you could even draw series of rectangles using GDI+. Pictureboxes can be found in Toolbox -> Common Controls -> Picturebox, while drawing the rectangles would be done in the panel's paint event. Moving the squares can be a little tricky, as you'll have to handle the: mouse down, mouse move, and mouse up events.