Box Shot 3D is a tool that will let you easily, and quickly design a virtual box cover for your program.
The only thing that you have to do is select the type of box, including ones for Windows Vista, and the images for each side.
The next step is to move the box into position (choosing the viewing angle), the lighting, the background, and the shadow.
It should be used as a complement to a photo editing program, as Box Shot allows you to insert images, but does not compose them on the box.
Watermark on the final image.