Where did all my disk space go? Every PC user asks this question at one time or another, and the answer can easily be found with a copy of WinDirStat. WinDirStat generates easy-to-understand graphical reports about disk usage, allowing you to see at a glance which individual files or folders hidden deep within a directory tree may be gobbling up dozens of gigabytes. A few other programs of this kind exist, but WinDirStat has consistently trumped them all.
Fire up the program and you'll be asked to select one or more drives or folders in your system, which are then analyzed for space usage. The analysis may take a few minutes or more, depending on how many files or directories are on the drive(s) in question; you can switch away and let the program run in the background. (Cute touch: The progress bars use Pac-Man icons.)
Once the analysis is done, the results appear in an arrangement known as a treemap, where the files that take up the most space show up as large colored blocks. This makes it easy to quickly spot the biggest space hogs. Click on any block and the top part of the program's window will display the corresponding file in the context of its directory, via a conventional tree-list view. You can also use the tree view to determine the relative space usage of the file or directory of your choice, so you can in effect drill down (or up) by either file size or location. Finally, files are color-coded by type, so you can see at a glance what kinds of files take up the most space.
It's also possible to do cleanup operations within the program. Right-click on a file or folder, and you can delete it -- either by sending it to the Recycle Bin or deleting it directly. You can also pop open a command line or Explorer window on the directory or file in question.
Unlocker and OpenedFilesView
Here is another scenario most of us have encountered: a file that simply can't be deleted because it's "in use." Windows Vista and Windows 7 are a little better at informing the user about which program is using the file in question, but sometimes you're stuck playing digital Whack-A-Mole trying to figure out which window to close.
I've used not one but two programs, at different times, to deal with these annoyances. The first is Cedrick Collomb's Unlocker, which many people know and love. The second is the lesser-known but still valuable OpenedFilesView (by Nir Sofer, author of BlueScreenView). Both do the same thing: Determine which process has a lock on which file, and let you release it either by killing the file handle or the offending process. However, they go about it very differently.
Unlocker runs silently in the background and adds a right-click context menu to Explorer. If you want to know what's locking a particular file, right-click and select Unlocker. From there you can elect to terminate the processes locking a file, make a copy of the file in question, or remove the locks that the process has on the file.
OpenedFilesView, on the other hand, provides a regularly updated list of all files currently locked by all processes, which can be sorted and searched. The same types of action can be taken, although OpenedFilesView doesn't support deleting a locked file or making a copy.
One major drawback to both Unlocker and OpenedFilesView is shaky 64-bit support. Unlocker doesn't work in 64-bit Windows at all. OpenedFilesView has a 64-bit edition, but requires that you disable driver signing system-wide (which requires a reboot). Turning this off makes it that much easier for unauthorized software to install drivers, although I'd bet most users who need a tool like this are well aware of those risks.
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Serdar Yegulalp has been writing about computers and information technology for over fifteen years for a variety of publications, including InformationWeek and Windows Magazine.
This story, "Top Free Troubleshooting Tools for Windows" was originally published by InfoWorld.