Folder Size is a free tool which helps you understand how your hard drive space is being used.

Launch the program, point it at the drive or folder tree you'd like to check (C:\, C:\Program Files maybe), click Start and watch as your system is scanned (a full C:\ drive check took around 30 seconds on our test PC).

On completion, Folder Size displays a list of folders in order of size. A separate pie chart presents a basic summary of the same data (you can switch this to a pie or animated chart with a click).

This list may not tell you very much, at least initially. 63.12% of our files were located in the Users folder, for instance - but which user?

To find out more, double-click a folder of interest, and Folder Size displays its contents only. This showed us which user had the most files; selecting that individual user told us their Downloads folder was a major space hog, and double-clicking Downloads displayed the ISO images which were the cause of our problems.

While Folder Size is free, the program does have Personal ($24.95) and Professional ($39.95) versions available which add extra features (they can scan network files, use command line switches, save/ load projects, filter your files, print results, export reports and more).

Slightly annoyingly, these features aren't left out or disabled. If you accidentally select one (File > Print) then you'll be told it's not available and asked to upgrade. This can be a minor hassle at first, but you soon learn what you can do, and what you can't, and the core features are more than enough to be useful.

What's new in 4.0.0 (see changelog for more)?

- Changed: Removed Adobe Flash dependency - charts no longer use Flash
- Added: Native 64 Bit version is now available - support for larger drives and faster performance
- Added: Improved support for scanning and displaying very long paths
- Added: Command line registration parameters in PRO version
- Added: Shortcut - ALT+UP - Folder Up (Same as Backspace)
- Added: Shortcut - Alt+Enter - Open the Properties dialog box for the selected item
- Fixed: Missing computer name on network locations


The interface is a little cluttered, but Folder Size is otherwise a quick and easy way to explore your hard drive usage.