WinDirStat (http://windirstat.info) creates a graphical representation of the files on your hard drive. Bigger blocks represent larger files, and the different colors equate to different file types. What does this mean? WinDirStat is essential for figuring out why your hard drive is full. Clicking a block takes you to its location in the file tree, allowing for easy cleanup. Intuitive navigation and easy “open in Explorer” options make this a must-have.