I am currently running Windows 7 on my C drive. I've allocated for it 25 Gb thinking it would be enough. It was enough until a while ago. Now it just keeps wanting more. I get low disk space warnings whenever I start the computer. No matter what I do it just keeps eating more.

I've moved big programs to D(>3.5 Gb worth) and it still isn't enough. As soon as I free something it takes a hold of it and goes to anywhere between 0 and 200Mb of free space. I've started going through folders and deleting program data that I thought the programs wouldn't miss(haven't ruined anything until now).

There are only 2 big folders on C: Windows 19.4Gb, Program Files (x86) 2.2Gb and hiberfil.sys 3Gb.

Can't even update Windows because there's not enough space. In the past few days when I close the computer it tries to install an update (Please don't turn off or unplug your computer) and it just stays that way until I force it to turn off.

What can I do? I really can't afford to install at the moment. Not for another month or so.

  • 1
    Welcome to Super User! Just to let you know, this is the perfect place for such questions! And you did a great job at asking it, nice detail and background info.
    – Wuffers
    Apr 21, 2011 at 5:45

6 Answers 6


Disable hibernate for now Click Start -> Type CMD -> Right Click on CMD and Run as administrator then run the command powercfg -h off then reboot this will remove the hiberfil.sys and not allow you to hibernate. You could also try adjusting the Pagefile size if it is really large.

Your problem is more than likely the Winsxs folder which grows over time as you use more software it keeps multiple copies of DLL's etc for maximum software support.

  • I never used hinernate. Maybe sleep once or twice. Regarding the DLL's I knew about them but this doesn't seem to be the issue. The memory disappears in a matter of minutes without me installing other software. Unless Windows is just downloading DLLs whenever it can.
    – Iustin
    Apr 21, 2011 at 6:05
  • Use Windirstat to check what folders have the largest amount of usage... windirstat.info. I was suggesting disable hibernate as something to do for now... what size if your pagefile if you have a large amount of ram you could possible lower that to a more reasonable size.
    – Riguez
    Apr 21, 2011 at 16:32

The main cause for the constant grow of used disk space is not the constant swap-partition, or (if you do not install any software) C:\Program Files\ but the WinSxS-Folder:

Why does the /winsxs folder grow so large, and can it be made smaller?

  • I knew about that one, but I don't think that is the case. I delete files / programs, and the freed up space just disappears. I don't install other programs in between. So unless Windows is downloading files without my permission, this doesn't seem like it.
    – Iustin
    Apr 21, 2011 at 6:22
  • have you read the link? every update to the OS increases the winsxs folder ... constantly .. and by measurable amounts. you have stated that your C:\Windows folder is 19gb ... which is a pretty good indicator about where your space is.
    – akira
    Apr 21, 2011 at 6:28
  • That doesn't seem to be the case. I free up data and it just goes away after I launch any program. The article mentioned Windows Update downloading the DLLs and I don't update after. I tried the first 2 solutions from there and they didn't work.
    – Iustin
    Apr 21, 2011 at 12:54
  • which is the biggest folder in your C:\Windows?
    – akira
    Apr 21, 2011 at 13:41
  • Yes, it is WinSxS. I couldn't compress as the first solution said even with administrator. Even if this is the cause, I am searching for a solution.
    – Iustin
    Apr 21, 2011 at 14:22

You could always repartition your drive without reinstalling Windows. There's free software to do that. EASEUS has been good to me: http://download.cnet.com/Easeus-Partition-Master-Home-Edition/3000-2248_4-10863346.html

  • If you go down this path make sure you backup in case something goes wrong like a power failure during transition could leave you with a broken filesystem.... you should always back up anyways :)
    – Riguez
    Apr 21, 2011 at 5:54
  • Good point to add! I would always make sure your data is backed up, but you could also image your hard drive before partitioning. There's free software for that, too, but frankly I don't think it's worth the hassle. If the partition happens to fail, then as long as you have your important data backed up, it'd be easiest just to install Windows again.
    – Compeek
    Apr 21, 2011 at 5:57
  • This isn't really an option do to the risk. If I could, I would reinstall. Back up is required in both cases.
    – Iustin
    Apr 21, 2011 at 6:06
  • Yeah, that's what I figured. You might be interested in the Tech Support Alert article on the best free drive imaging software: techsupportalert.com/best-free-drive-imaging-program.htm
    – Compeek
    Apr 21, 2011 at 6:27

Use SpaceSniffer to visualise for certain which are the "culprit" directories within Windows. As stated previously, it is most likely WinSxs that is maintaining the large cache of OS components.


You'd have to use a partition resizing software like Acronis Disk Director, or backup software with the ability to restore a partition with the option of resizing it to fit a larger disk.


Check out WinDirStat to view which files are using up space on your harddrive.

The other responders have given you most of the likely causes. I would go with resizing the Windows partition (no need to reinstall). So if you have enough space on D:, backup your data and then use that space to resize.


Try running

fsutil usn deletejournal /n C:

if you don't use specialized backup software, and seeing how much space it frees up.

  • 1
    maybe you should explain what this does and what the consequences are ... otherwise it's as good as rm -fr /
    – akira
    Apr 21, 2011 at 11:12
  • support.microsoft.com/kb/837325 here is the technet entry on the command... it lowers reserved space for the USN journal apparently
    – Riguez
    Apr 21, 2011 at 16:34
  • @akira: It deletes the USN journal, which is used by backup software to detect changes to the drive.
    – user541686
    Apr 21, 2011 at 17:19

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