I'm helping a small customer analyze disk usage on a Windows server so they can identify the folders and files consuming the most space and remove data that is no longer needed. I'd prefer a free, easy-to-use tool with a clear visual overview of disk consumption. WizTree, WinDirStat, and TreeSize Free all seem like possibilities. Which one has worked best for you, particularly in a small customer environment?
4 Answers
I’ve used both WinDirStat and TreeSize, and either can do the job. Trying both is probably the best approach since the layout and performance may suit different people. Just verify the licensing and operating-system support before using TreeSize Free on a Windows Server installation.
Scanner is extremely simple and has been useful for quickly seeing what is taking up space. However, its last release appears to be quite old, so I’d favor a more actively maintained tool for a customer environment.
That’s the main concern with older utilities: even if they still work, newer tools are generally a safer long-term choice for compatibility and support.
For a smaller portable utility, FolderSize is worth considering. It’s lightweight and straightforward, though it doesn’t offer as much visual detail as the larger disk-analysis tools.
WinDirStat is a solid choice. It’s free, open source, reliable, and gives you both a folder breakdown and a visual map of disk usage. The main downside is that scanning can be fairly slow on larger disks.

TreeSize Free may be limited to desktop versions of Windows, so a server deployment could require a paid license. Check the current vendor terms rather than assuming the free edition is covered.