Side-By-Side Explorer is a small program that lets you open two simultaneous windows in Windows Explorer, side by side.
Each one of the Windows Explorer windows opens to a previously designated folder, making it easier to compare or transfer content between them.
Side-By-Side Explorer lets you configure a list of window/folder pairs, and access them any time from the system tray menu. You can also use the program in regular individual sessions, as a shortcut to your favourite folders.