How many times have you run out of space on your C: drive and wondered… where did all my free space go? The answer is a great little freeware utility called DriveSpacio that helps you find out where all that free space has gone, similar to the more well known WinDirStat utility. The benefit of using this one is that it integrates directly into the Explorer shell and has a lot more reports.
Once you've downloaded and opened the utility, you'll see a screen with the hard drives in your computer. For instance, if you look in my Computer dialog, you'll see 3 hard drives and some other USB drives. So the Drives tab in DriveSpacio will show you a graphical view of all drives on your computer, with all sorts of great charts and graphs. Different views are offered, such as pie charts or the bar graph.
DriveSpacio integrates into Windows Explorer so you are able to right click on a drive and analyze it. You can also launch the application and open a specific drive, or even just a specific sub-folder if you want. I find this to be helpful because I can choose to only look in my user folder.
Source:→ The How-To Geek