I download lots of huge files all the time, i often delete them and download other files. I also rip a lot of my DVD's to my mac, and often work with large files. In windows i often defragmented and disk cleaned my HD's because i was told so. I downloaded cocktail (which many MR's people recommended) and would like to know how to use it? I dont want to mess anything on my Mac so i would rather get a few pointers here.