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How can I tell what's taking up so much disk space?

Question: My hard disk keeps filling up. I know I can do things like delete temporary files, the Internet Explorer cache and the like, but it seems like there’s something else taking more space than it should. Is there a way to find out?

Absolutely. In fact, slowly losing disk space is one of those things that’s not only annoying, but can often be a sign of a problem such as a virus or spyware.

Fortunately there are free tools available to help figure it out.

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Since you’ve already done the usual things to free up disk space, we’ll  tart with a couple of things many people don’t try.

In a command prompt, run:

chkdsk /f

That will probably tell you that the drive can’t be locked, and would you like to run it on next reboot, to which you would answer “yes”. Reboot the machine – as part of the reboot, it will now run a thorough scan of the hard disk and correct any logical errors that may have been introduced. Quite often these types of errors can be introduced when a program, or your computer, crashes. Using (diruse) we can find out where, on your hard disk, the most space is being used.”

Now, I’ll warn you that if the disk is really corrupt, whatever the cause, the result may be some lost data as well. I’d definitely recommend backing up or copying off anything that you’d consider critical.

But my motivation in mentioning chkdsk here, is that it’s also possible that the process will free up a bunch of disk space.

Now, as to identifying where all the disk space is being used, go download the diruse tool from Microsoft. Using this tool we can find out where, on your hard disk, the most space is being used.

After installing the program in the default location, in a command prompt, run:

cd "\Program Files\Resource Kit"
diruse /s \ | sort

This will take a little while to run, and then all of a sudden a list of things will come flying by the screen. When it finally stops, the end of the list will show you the directories that are taking up the most space. For example on my machine it ends like this:

  876171666   7065  \i386
  959769713     14  \Program Files\Microsoft Streets and Trips\Data
  Size  (b)  Files  Directory
 1063624662   1127  \Program Files\Microsoft Visual Studio .NET\Msdn\1033
 2684179043     13  \
30070896690  135246  SUB-TOTAL: \
30070896690  135246  TOTAL: \

Ignore the size, total and sub-total lines. The biggest directory on my machine is the root directory (just “\”), which contains the system swap file, and the next biggest is the “Msdn\1033” directory within my Visual Studio installation, which contains the on-line product documentation. Your list will, of course be much different.

Once you see which directories are the largest in terms of used space, perhaps that’ll give some clues as to what you might be able to do to recover it.

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37 comments on “How can I tell what's taking up so much disk space?”

  1. I cleaned up my disk and i ticked the compression of old files. Is that a problem? I also installed adobe acrobat 6 pro and when i entered Outlook it said that i have to accept some macros from adobe, it never asked me to accept anything before despite that i had adobe reader 7 installed, it says something about Anyway, after that i recovered my pc to a date that i hadnt installed acrobat 6 pro and when i opened outlook it said the same (it wasnt supposed to say anything, because in the recovery date no acrobat 6 was installed). Is there something i can do to sort things out? Thanks in advance.

  2. diruse provides some cursory information about disk usage, but my favorite app for keeping track of disk usage (on my local computer and across my network) is Disk Triage. The app allows you to trend disk usage and watch for specific file types filling up hard disk space. Graphing and charts provides visual information about where your drive space is being used over time and in general offers some of the best details I’ve ever found for keeping unnecessary files from clogging my hard drive. It’s not free, but the file management is well worth the price. Combining it with an app like the free DupKiller to eliminate duplicate files and you’ve got an optimized solution for keeping your disk space usage to a minimum.

  3. Or the reason might be the files/directories saved by the System Restore NT-service, i.e. this folder is to used to store various system/configuration changes.

    If you want to get the space back, i.e., get rid of all those files under directory usually named “\System Volume Information\” (however, note that you can’t browse it), and located in root of a NTFS-formatted drive, one just needs to disable or stop the System Restore service (or just set it to Manual startup-type), reboot and enable/start it again; of course if one is confident enough to mess with “services.msc”. Another option is however, to only delete all the “restore points”. Ah yes, and just as a further information; also note that these files/directories cannot be defragmented by Windows built-in defrag program.

    best regards,
    Ivan Tadej, Slovenija, Europe

  4. This solution is simply not good enough! The best way to find out your disk usage is like Jake Ludington said, use a disk space analyser, except the one he mentionned, “Disk Triage” is software. I’m using (since 3 years now) a FREEWARE called TreeSize and its available here: It shows you a Directory tree listing with its size and percentage of space on the left, it also orders the directories from biggest to smallest. It is very useful and simple to use, I recommended to anyone who wants to free up space!

  5. By far the best tool to know what is taking up space on your hard drive is ZTREE, an old program which was developed during the early DOS years and originally called XTREE.

    Among many other easy to use features, this program allows the user to list all files in order of size, date, name or extension. It is also easy to put in file specs such as *.tmp and *.bak or *.swp and view all such files with the goal of conveniently deleting those of no value with a few simple key strokes.

    Some of the particular disk cleaning operations which are made possible by this program are to look for duplicate files located in two or more directories or partitions, copying selected files or groups of files to other drives or CDs while preserving their tree structure, or quickly determining which files have been modified on a given day to allow an incremental backup of a full day’s work in less than a minute.

    Although other disk maintenance programs may have more modern interfaces, nothing can compare with the effectiveness and ease of use as ZTREE (note: I have no affiliation with the authors or sellers of this program.)

  6. That’s an “interesting” display they use. HOWEVER I almost gave up on them totally because of the popup ad that was totally blocking my access to their site. BAD BAD behaviour … especially for a university.

  7. I really like WinDirStat. It is free open-source software pulished under the GNU General Public License. It allows you to sort files/folders by size, percentage of disk space, etc. It also provides a graphical view that makes spotting the space hogging culprits a piece of cake.
    You can download it at

  8. Hi,
    I was having a problem regarding this disk space. My drive was 4.65 and only .5 gb was left empty. I tried disabling the Sytem Restore on all drives. Instantly the free space became 1.88 gb. And I haven’t tried a scan disk or even a reboot. Thanks Ivan, your suggestions saved me.

  9. My computer is a fairly new hp laptop, it is less than a year old. Recently I went to defrag it and relised that I only have 44% of my memory left and cannot find what is eating it all up. I deleted all of my pictures and all but 8 gigs of my music. I have done everything this page says to and have tried multiple temporary file removers(ex CC cleaner). nothing is working. I have almost nothing on this computer except mozilla, AOL, internet exploere. When I run programs like diruse I get results saying that my music is taking up the majority of the space (which only totals to be 44000 MB), but I know there is only eight gigs of music on it and my computer has the capacity of 84 gigs. I have had norton as my virusware in the past and I am currently using symantic. I cannot find what is eating all of my memory. got any ideas?
    thanks kara
    p.s. yes my windows is updated and as is my ad-aware and symantic

    Hash: SHA1

    Sure! Use “more”:

    diruse /s \ | sort | more


    Version: GnuPG v1.4.6 (MingW32)


  11. I just want to say a great big THANK YOU for this very valuable information!!! You’ve just saved my sanity! Your instructions and information on diruse helped solve my problem. Thanks, again!

  12. I’ve been losing approx. .5GB of free space per week(I have 80GB hard drive). I’ve tried all the normal stuff,can’t stop the loss or find out where it’s going. I read your article and downloaded DIRUSE,but cant open or run it. It appears to be for windows 2000. I have xp. Any ideas? I’m just about ready to give up and reformat.

  13. Why,when I check the capacity of my hard disk, I see free capacity is 10.4GB and used capacity is 30.5GB.But,when I check all files and folders in the same hard disk, their capacity is only 13.6GB.I think it is not a virtual memory because it is too large difference.Please help me the reason and how to repair.My laptop is T61 Thinkpad.
    Pls send me email.Thank a lot.

  14. Diruse – useful – But what then…?
    I originally checked my usage on C:\ with Easy Cleaner Space Usage and got a print out showing \winxp using 33% of 16.6 GB (\system volume information uses 10% & \program files 13%)…
    Why should WinXp need and use such a wadge of my hard drive and what (If anything) can I do to reduce it…?
    Thanx in advance Leo

  15. im losing memory on my hard drive ive got 80 gig ive done the usual stuff i dont have much on my computer and yet i have 50gig left and it gets less each week how do i stop deleated folders bieng saved on my hard drive thanks.

  16. This process worked for me. I used to have 88.3 gb remaining on my HDD out of 140. Now I have 109gb remaining. Run disk clean up. Go to more options on the second tab. Go to the second part where it says remove restore points and shadow copies, press up clean up. This removes all of the restore points until the most recent one.

  17. You dont know what your talking about it didnt work it only works for microsoft xp proffesional and windows 2003. You should explain that to people.

  18. I am running XP Prof, SP2, why is IE7 taking up so much memory? My system slows down or just completely stops in the middle of loading IE, I’ll check what processes are taking up so much memory and it’s IE, why so much? I do check for Spyware and download updates but it seems IE7 is using a lot of memory.

  19. How can I do the same thing for windows xp? What do I type in the run screen after i download the diruse and all that came with it from microsoft?

  20. I have a Windows 2003 server and having similar issues. I’ve tried the tree size, disk cleanup, defrag, etc. and I am not seeing anything outside of the ordinary…but my disk space is being eaten away. I am using only 6.19 GB of space when I get the size from the folders, but it says that I have only 51 GB of remaining space (on a 150 GB drive). I know some is used for the swap file (1.5 GB). Nothing else exists.

  21. i keep loseing free space i keep deleteing old files.i not useing .but i keep lose free space why/ can some one help.i have windows vista basic

  22. Still haven’t used Disc Clean up as I haven’t a clue as to what to keep and what to delete.Being a frightened that I might lose something essential, can you advise on what is reasonable to delete.Many thanks

  23. I have an odd problem,i have a small hdd of 80 gb,10 of these are used for the C:\ drive,right now i have less than a gb of free space,800 mb more precisley,so i should have at least 8 gb of space used(my C:\ drive is not exactly 10 bg),but when i check the space used by all the files on my C:\ drive this is what i get :Size:7.02 and Size on disk 5.87 GB ,what could cause this?

  24. One thing to remember is that when you are deleting files, if all you do is hit the “delete” button, they will normally end up in the “Recycle bin”. Still using up space. Go into the recycle bin and clean it up too. Or use a tool like ccleaner to explicitly cleanup the recycle bin.
    Or when you are deleting files, press and hold the SHIFT key in combination with the delete key to bypass the recycle bin.

  25. Easycleaner has identified the System Volume Information as being the largest folder on the HD. OK – we know which is the biggest but what, if anything, is safe to delete within that folder. I have a bunch of sub-folders labelled RP239 to RP334 with dates between 16/01/2010 to today’s date (12/04/2010) (English date system!) In some of these sub-folders are shortcuts to documents I’ve used and AdAware logos plus dlls and ini files and references to the registry – eek!
    Can I clean it up? Should I clean it up? If Yes to both – how?

  26. Leo I ran the chkdsk and it went through the motions and completed and restarted.I then checked the free disk space still said 3.57gb free out of 325gb disc c pie is complete blue with a sliver of pink (freespace) dont know what else to do I have delete every picture and program that i think i can delete frustrated can you help me not to computer savy but trying

    Try this article: Where’s my disk space going?


  27. I downloaded diruse and installed it. But, it just flashed on and then off quickly. I didn’t get to read it. Also, the “cd “\Program Files\Resource Kit”
    diruse /s \ | sort” command prompt thing did not work. Please help.

  28. Ok I did all this and Downloaded from Tree Size and WinDir. Came up with 1 file that is in “general” tab 785 gb. but can’t open it at all so I don’t know what it is. Can anyone help?


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