Clickfree HD535 500 GB Hard Drive, 3.5" External

HD535 offers incremental backup; upon first connection it will automatically find all of the user data files and copy them to the hard drive. Each time after that, it will only back up the new files or the ones that have changed.

While the software's default settings will probably be sufficient for most users, it is user-modifiable, providing full control over the backup settings. Even after the settings have been changed, the backup will still run without any user interaction.