Im not running Windows in the back ground, nor am I running Mavericks yet. I do have some large video files from home movies. I try to finish one, make a hard copy, then let Time Machine back it up. If I am understanding correctly, each time I make a change / work on the video, Time Machine will make a complete backup. Correct? I have not worked on videos in a few months (no time). Does this hold true for slide shows as well? My wife will tweak a slide show several times before finishing it. The shows are rather large (30 mins to an hour) Also, because TimeMachine is making several copies of Movies as I work on them, can I keep a final version on the backup and delete all others?