If you haven’t been organizing and discarding files as you go, it’s likely your hard drive is stuffed with downloads, unwanted photos, file copies and other digital dust bunnies. This can reveal itself in slower performance, that unsettling humming noise, and the Mac’s dreaded spinning wheel or Windows’ inverting hourglass. You may even have, like me, taken advantage of the Mac’s awesome Migration Assistant to shift all your documents, files and settings from one Mac to another — only you now have duplicate Downloads and Documents folders in different destinations, causing bafflement every time a file is saved. Deep cleaning your computer of unwanted files and streamlining your folder system can not only free up storage space, but improve your computer’s performance.