Why did 30 GB of space disappear from C drive in less than one week?

Nancy Cummings July 16, 2012
Pinterest Stumbleupon Whatsapp

I have difficulty opening MS Word, Excel, etc. I noticed that 30 GB of memory was missing since last week. I ran Malwarebytes, found nothing, Kaspersky deep scan, found nothing. I downloaded nothing. But, last week, I compressed some documents. I thought this would make more space. Operating any program is time consuming. How do I find out what happened?

Ads by Google

  1. Matthew McNamara
    July 16, 2012 at 11:02 pm

    So this is a bit out there in terms of the realm of possibilities, but the same thing happened to me last week. I used WinDirStat (http://windirstat.info/) to visually show me the largest files and it turned out there was one 20+GB file that had eaten up my SSD space.

    Turns out it was a log file. When I googled the file name it was an arduino log file that grows huge if you disconnect the usb from the board (generating a serial error) and keeps growing until you close and open the ide again. If by any chance you are playing with an arduino, it may be worth looking into.

  2. Gaurav
    July 16, 2012 at 6:46 pm

    This can happen, if crash files and dump files are created by windows. Also at some point windows also keep shadow files which are used as a restore points. These also gets accounted towards 30GB or more sometimes. it depends on what system you have (OS) and how it was functioning till the time you recognised this issue.

    • Nancy
      July 17, 2012 at 1:03 am

      Where will I find Dump files? Can they be deleted?


  3. Sohel Zaman
    July 16, 2012 at 6:44 pm

    Trying using TREESIZE free/pro. You can see all the details of every file which occupies how much space in that particular drive. That way, you may be able to find out the missing 30GB.

  4. Ben
    July 16, 2012 at 4:51 pm

    Try using the Disk Cleanup tool, just to rule out clutter from unnecessary files

    • Nancy
      July 17, 2012 at 1:46 am


      Still same. I ran WinDirStat. Found over 40GB of Kaspersky log files.

  5. Oron
    July 16, 2012 at 4:44 pm

    I'd suggest using Space Sniffer, which I prefer to WinDirStat (but both are pretty similar, to be honest). These will show you which folders & files are taking up the most space.

  6. illegal3alien
    July 16, 2012 at 4:11 pm

    My favorite is WinDirStat. Like other programs, you run it and it will report what files are taking up the most space. After it finishes, but click the largest boxes at the bottom and it will tell you what the file is. If you're not sure, report back with information on the file name and location and someone should be able to tell you what it is and how it got there.

    • Nancy
      July 17, 2012 at 1:02 am

      I downloaded WinDirStat as you recommended. It seems that most of the new files are related to Kaspersky. There is something very strange. There is a "Change" dated 7/24/2012. However, most of this is Kaspersky. I cannot understand how or why this would happen. I will contact them. There are other video files from years ago that are taking up lots of space, but they have been there for years. This is all since July 4. The largest Kasperky file is 17.0 GB dated 7/10/12:
      C:\Documents and Settings\All Users\Application Kaspersky Lab\KAV.
      another is 5.0 GB dated 7/13:
      C:\Documents and Settings\All Users\Application Data\Kaspersky Lab\KAV.

      What next?

      BTW, Thanks for recommending WinDirStat. I think it is great! I found some old files and plenty of duplicate files as well. Is there anything that will remove duplicate files found in different places?

      I see strange times changes took place as well such as today at 11:42:30 PM when at this moment in time the date is correct the time is 8:53 PM.

      • Arrow Quiver
        July 17, 2012 at 1:29 am

        Since these are just log files (not quarantined apps/files or anything), then I would probably say it's safe to remove.

        Or maybe all of the other .LOG files under this folder:

        C:\Documents and Settings\All Users\Application Data\Kaspersky Lab\

      • illegal3alien
        July 17, 2012 at 2:29 am

        I would be careful deleting both of them. Logs that big indicate either Kaspersky is malfunctioning, or having some sort of problem. I would download http://download.cnet.com/Large-Text-File-Viewer/3000-2379_4-90541.html to open up the logs and save a big chunk of the bottom. The resulting file should be around 10MB. Once you save the last chunk of each file, Kaspersky will probably want this to help determine why the program is logging so much information. If it says the file is open in another program, try temporarily disabling Kaspersky. You may also need to go into services.msc (Start > Run) and look for any Kaspersky services and temporary Stop them (by right clicking). After you get the files removed, restart the computer to be sure Kaspersky gets restarted and running again.

  7. Mihovil Pletikos
    July 16, 2012 at 4:03 pm

    when you said missing is that it is gone from the disk space of just used up?
    if it is gone from the disk space maybe you have some errors on the drive. if not install ccleaner and just run it to find if something can be recovered

    • Nancy
      July 16, 2012 at 4:20 pm

      I should have clearified better. I had about 95-100GB free space (total 293) now about 64-70GB. I am not using that computer right now so I do not have exact numbers. Total space remained the same.

    • Nancy
      July 17, 2012 at 1:54 am

      I started noticing early last week. Cleaned everything and recovered 3 GB by compressing my documents, deleting cookies, temp files and old stuff.

      Then I had more trouble booting and once last week, I checked space and saw nearly 35GB was used up somehow. I was totally stumped. I did not download anything but I did leave the computer running a couple of nights while I scanned for viruses and malware. All this occurred since last weekend, July 6 or 7.

      The drive space was used not missing. I should have made it clear in my original inquiry.


      • ed little
        December 3, 2012 at 8:06 pm

        Could you be supplying your extra space to the "cloud" for use as storage space by other people?

        Where is the "cloud" anyway?

        • Nancy
          December 4, 2012 at 12:55 am


          Thanks for your inquiry. I found that my new Kaspersky subscription offered an option to participate in Kaspersky's Security Network. The storage space was used by Kaspersky's log files. Nearly everything my computer did was logged. I have since then removed my option to participate and communicated with them regarding the space used.

          After installing and running WinDirStat, I was clearly able to see the largest files that changed overnight were Kaspersky's log files.

          I have had many hours of successful operating since I removed my participation with Kaspersky's Security Network.

          Things are now working fine. My computer is getting pretty old and I have no intention in replacing it.

          As far as the "cloud." I have no idea where it is, only that there is lots of space in the cloud. FOrtunate none of is supplied from my hard drive.


  8. Rob Douglas
    July 16, 2012 at 2:10 pm

    I'd try having a look at the results of WinDirStat - http://windirstat.info/. It'll show you exactly where the space is being consumed

  9. ha14
    July 16, 2012 at 1:26 pm

    download Treesize free version and do scan, see where are the big files and check if they match 30GB

  10. Alan Wade
    July 16, 2012 at 11:06 am

    How many hard drives do you have? If space is a problem on the system drive usually C then look at moving the page file will free up many gigabytes of space.
    This can also be your problem if you have been using specialised cleaners which would delete the pagefile then recreate it. Of course if the pagefile gets corrupted then that can give you a sudden loss of space.

    To move it assuming you have either a partitioned drive or an extra hard drive is very easy and you will see the difference directly and you should see a difference in overall performance.

    To move it click on Start, right click on Computer and select properties.
    In the left hand pane select Advanced System Properties.
    Click the Advanced tab then in the 'Performance' section select Settings.
    Now click the Advanced tab and in the Virtual Memory section select Change.
    Uncheck Automatically Manage Paging File Size for All Drives
    Choose the drive/partition where you want your pagefile to be stored and select System Managed Size from the list of options then press Set.
    Select your system drive (usually C) click on Custom Size and make the Min and Max 1000 MB.
    OK your way out and reboot.
    Your pagefile will now be rebuilt which will temporarily slow down down your computer for a little while. So its best to do this just before you are going out etc.

    Of course as I said there was a couple of assumptions there with drives and partitions but that will free up space on your C drive and give you a little performance kick.

    • Nancy
      July 17, 2012 at 1:12 am

      C and D I will do as you say and see what will happen.
      Thank you.

      • Bruce Epper
        July 17, 2012 at 8:02 am

        Just a few comments about playing the the pagefile:

        1. Reducing the size of the pagefile may have a NEGATIVE impact on system performance based on the amount of RAM in the system and how the system is used during normal operation.
        2. You will get better performance if the size of the pagefile is a power of 2, so instead of making it 1000MB, make it 1024MB.
        3. Many systems have a single hard drive partitioned into 2 parts and thus having 2 drive letters. Moving a pagefile from one to the other will have no impact on overall performance since it is still residing on the same physical device.
        4. Those systems that have a single drive with two partitions generally have the second partition configured with the image that is used for the manufacturer's system restore operation (not to be confused with the Windows System Restore). It should be set up as a read-only partition, so you may not be able to put anything there anyway, but if it isn't you run the risk of damaging that restore image so do this with extreme caution.

        If you do not hibernate the computer, you can always turn that off and reclaim the space used by hiberfil.sys on your system drive. To do this, open an elevated command prompt (Start -> type 'cmd' (no quotes), right-click cmd.exe and select 'Run as administrator'. Type 'powercfg -h off' and press Enter. Close the command prompt by typing 'exit' and pressing Enter.

  11. ferdinan Sitohang
    July 16, 2012 at 10:47 am

    Please check from task manager, which one of your program consumes lots of resources. About your 30 Gb HD. Try to clean your temporary file. Actually windows OS is creating lots of junk file, it is why you need to clean your drive. It will shows you, how much capacity drive that can be free from your drive.

    • Nancy
      July 16, 2012 at 4:15 pm

      I check the Task Manager routinely. The only memory user was Firefox and Kaspersky which remained the same.

  12. Mike
    July 16, 2012 at 9:47 am

    Well, 30GB of space don't vanish ~ there has to be something filling it up, be it log files, crash dumps or whatever.

    I suggest using a occupied disk space analysis tools like jDiskReport or similar. This will show you where (directory tree) the space is used and/or by what files.

    If by compressing you mean the NTFS compression you can select via the right-click options I suggest to use it with caution.
    There will be no problem compressing office documents but the savings are probably quite low. In other cases e.g. applications (especially anti-virus) or large files it may result in errors.

  13. Kavs
    July 16, 2012 at 7:34 am

    Compressing your files to create space on your drive is not a great idea as the after effects is that programs tend to run slowly as they need to be uncompressed before use everytime. hence the reason you have applications running slowly on your drive.

    You always have to weigh out whether its absolutely necessary to compress your Drive.

    Better option would be to move your massive files into an external Hardrive which come pretty cheap these days.

    Your 30Gb missing is a big number but without seeing your pc we would not be able to tell you exactly what has happened but a few suggestions would be maybe you had a microsoft update happen that created tempory file. Cookies and tempory Internet browsing data has been saving massive amounts of files into your drive etc.

    Browse to this link and read step 2 which shows you how to do a disk clean up to free your disk space with files that can be deleted and are just browsing files.


    hope this helps buddy

    • Bruce Epper
      July 16, 2012 at 12:29 pm

      OP said she "compressed some documents", not the entire drive so your comment about compression is completely irrelevant with regard to system performance.The "missing" drive space could be due to system updates, dump files, logs, misc temp files, etc. It can also be due to the amount of space reserved for System Restore.To find what files were added or changed in the last week, open Windows Explorer and click in the Search box in the upper-right corner. Click on the 'Date Modified' link, then eiher select a date range with the calendar or click the link for 'Last week'. This will find all files that have a modified DTS during the previous week so you can see what recently changed/added files are consuming the space (as long as it isn't your System Restore files).

      • Nancy
        July 16, 2012 at 4:24 pm

        How will I know if it the files are System Restore files? And, how can I remove old System Restore points? I tried to use System Restore many times and nothing changed. A message was returned stating the system could not be restored.

        • Bruce Epper
          July 17, 2012 at 7:44 am

          Files that are in System Restore are marked as superhidden. This simply means they moved to a directory that is marked as system & hidden and Windows will not display them with the default configuration of Windows Explorer. If you are using Win 7, you can right-click on Computer and select Properties from the context menu. Next, click on 'Advanced system settings' link then the System Protection tab. Highlight your C: drive under Protection settings and click on the Configure button. From here, you can turn System Restore on or off as well as view the current drive space used for restore points and the max amount of space that can be used for restore points. You can also delete all of your old restore points from here. You normally should not delete all restore points unless there is a very good reason for doing so. Instead go to the properties of the drive and click on Disk Cleanup (on the General tab). Click on the Cleanup System Files button, then switch to the More Options tab. In the System Restore and Shadow Copies section, click on the Cleanup... button. There will be a confirmation dialog that appears to make sure you really want to do this. Clicking on delete will delete all but the most recent restore point.

    • Nancy
      July 16, 2012 at 4:13 pm

      I only compressed my documents. No programs. I removed unused programs, deleted cookies and temporary browsing data. I searched recently modified files which returned thousands of files related to programs. I did not touch. I have no idea what they but most were related to Firefox, Kaspersky, Malwarebytes, etc. All were less than 1MB. I did not remove restore points. System Restore does not work for some reason.

Ads by Google