I am a videographer and I back up all of my client files onto two separate hard drives for archiving (in case one would die on me), so I copy the same thing to both of them. Occasionally, I have to go back into a project and update some files or make other changes. The problem is that after making these changes I'd like to pop in the second back-up hard drive and sync the two with the newer files.

The way I do it now is just using the Windows Explorer (Windows 7) to copy the folders from one hard drive to the other. Then I have to wait for it to see that some of the files are the same name and I have to make sure that I overwrite the files that have been updated and not copy the ones that haven't changed (for time reasons, because many of them are large video files).

So, is there a free piece of software out there designed for what I'm wanting to do? Basically get options when trying to sync up two hard drives so that only the newer files are overwritten.

Much Appreciated.