Windows Double Explorer is a free to use program which allows you to have more than one explorer window opened up in single application, you don’t need to open two separate explorer windows and then align them side by side or stacked. This application by default allows you to use more than one explorer window so that you can carry out the files drag and drop operations and other task easily.
This programs offers you two basic layout, shown below
Side By Side Layout [ Vertical ]
Stacked Layout [ Horizontal ]
You can easily switch in between these two layouts easily just by a mouse click. This application comes in two formats, the first one is installer with which you can install the program and second is the portable version which you can directly run without installing. This application works for windows xp, vista and windows 7 too.