Updated: March 17, 2014
If you want to know what files or folders take the most space on your local disk, what do you do? Easy. In Linux, you use df and du, and William is thy uncle. On Windows, you scratch your head and wonder. But worry not, there's a nifty tool for you. It's called Windirstat, and it does just that.
This software is the Windows implementation of Kdirstat, a Linux utility that can examine your storage devices and display useful statistics, including largest directories and files, sort usage by file types, show you a topography map, and more. Anyhow, this same behavior and fun is also available for Windows people. Let's tour, shall we.
The setup is very simple. On every launch, you will be asked whether you want to examine all your drives or a specific device. Now, Windirstat can traverse network paths, too, so if you have remote filesystems in use, you might want to consider being slightly conservative at first, to shorten the scan time and reduce the load. Then, once you are somewhat more comfortable using the tool, you can expand elsewhere.
Windirstat can take a while to run, especially if you have slow disks with lots of data. While you're waiting, as a sort of geeky entertainment, it will display little Pacman thingies running left and right. Oh joy.
Windirstat display information based on size, although you can use other available categories for that. You will learn how much space your data takes, when it was last changed, the number of items, subdirectories, and more. A very good start for some home cleaning.
Then, once the scan is complete, you also get a lovely color map, showing you the distribution of your data, using a color code. For example, in the scenario below, you can see that various application libraries take 6.2GB, while system files take 1.6GB, with fonts in the respectable third place. It looks cool, plus it's quite efficient. And you can always rescan to get changes.
Cleanup might be your next step, but I would be prudent, and make sure there's a proper backup in place, in case you botch something. Then, in the settings menu, you can make additional changes and tweaks to the tool's behavior. If you don't like the treemap, you can remove it. Moreover, you can specify the depth of search, the cleanup policy, and more. You can also produce a report. Or remove the pacman animation.
Windirstat is a very useful tool for Windows people. I must admit I have been using it quite often ever since Windows XP, and it's still very practical and useful on the more recent versions. It probably won't render miracles, but if you're really short on space, you might discover that odd extra GB you never thought you could reclaim. Windirstat is also useful in helping you maintain a well laid out disk. Quite recommended.
And I'd like to thank Mahdi for this recommendation!