Robocopy is one of multiple tools that can be found in the Windows Resource Kit, which you can find here. It is a simple, but powerful command-line based copy tool to securely copy, mirror and relocate from a source to a target. It is not suitable for real-data synchronization, since it replicates data from the source to the target rather than comparing both sides to find the latest file version. But it is an excellent and efficient choice if you want to create a full backup (copy everything to a new location) or copy only incremental changes (copy to and update an existing location). Be careful with copying to existing locations: Robocopy will remove files on the target that no longer exist on the source.
Luckily, you don't have to open command line prompts to equip the Robocopy executable with the parameters for your copy or replication job. Copyrite XP version 1.1 is free a GUI tool designed to operate Robocopy (version 1.4 costs $ 10). Copyrite helps you to build your own copy job and save it as batch file, which can easily be executed or scheduled for a later execution.