Windows 10 unexplained os size fluctuations

  1. Posts : 459
    Microsoft Windows 10 Professional (x64) Build 19044.1706 (21H2)

    Windows 10 unexplained os size fluctuations

    One day, A while back, I got a desktop notification that my os partition was was running out of room.

    This was totally unexpected. Previous to this, my 40 gb partition had about 15gb free, and suddenly I only had 200mb of free space available.

    It was not a result of a recent windows update.

    All my data is on a separate partition, and I make it a practice to only use portable programs whenever possible, situated on the data partition. I have a standard set of programs installed on the OS partition which rarely varies except for updates, and certainly nothing that word cause a sudden occupancy of 15g.

    I use Macrium, so it is a simple task to go back to a time when the OS size is normal. When this first happened, I restored a backup image, and did my windows updates, after which things seemed to be back to normal.

    But again, a few days ago, it happened again. I cant say exactly when, because I dont regularly check the OS size, but I did check it after the last windows update, and it looked normal, and no major changes have been made since.

    I again did an image restore and the windows updates, and closely kept a log of the OS size. It was initially 11.1gb of free space.

    I also noticed that rebooting the computer would result in size fluctuations. But maybe this is normal?

    I then did a disk cleanup which found a whopping 10.9gb of windows update files (which were not there before the image restore), which I deleted, but it only got me back to 12.6gb free.

    A few more reboots, and I now had 16gb free. It has now settled in at 15.5gb free.

    The size of my OS now is 24.4gb...about what it should be. Because the image I restored was a few months old, I still have to tweak a number of things, but the major space eaters are already in place and up to date.

    I'm gonna watch it closely. It's been 2 days now.

    I'd like to know if this has happened to you.

      My Computer

  2. Posts : 459
    Microsoft Windows 10 Professional (x64) Build 19044.1706 (21H2)
    Thread Starter

    Maybe someone could answer this.

    I came across a thread that mentioned Windirstat.

    I ran it and the hiberfil.sys size is 6.3gb. As far as I know, I have Hibernate disabled, so I don't understand this.

    Could it be that I had Hibernate enabled in the past and the file remained there? Of course, that wouldn't explain my free space fluctuatons, would it?

    The only other conclusion I can figure is that my ssd is failing.

      My Computer

  3. Posts : 1,471
    Win10 Home x64 - 1809

    Hey kipzyxmsir,
    FYI on the Hyberfile.sys ....

    Windows Fast Startup also used the hiberfil.sys. Check the following tutorials ...

    Fast Startup On/Off - Turn On or Off Fast Startup in Windows 10 Performance Maintenance Tutorials

    Fast Startup with reduced Hyberfile - Specify Hiberfile Type as Full or Reduced in Windows 10 Performance Maintenance Tutorials

    Enable / Disable Hybernate - Enable or Disable Hibernate in Windows 10 Performance Maintenance Tutorials
      My Computers

  4. Posts : 459
    Microsoft Windows 10 Professional (x64) Build 19044.1706 (21H2)
    Thread Starter

    Hi Eagle51,

    Sorry, I didn't realize I has gotten a reply. Thanks for answering and that was a very helpful tip,
      My Computer

  5. Posts : 2,767
    Windows 10 Home x64

    40GB for a system partition may be too small. 75-100GB is fine. I can cope with 50GB but you must know what you are doing. You may need to use compact command to get more free space.
      My Computer

  6. Posts : 5,202
    Windows 11 Home

    I run [Batch] Windows Cleanup after every successful windows update. Note, that a single graphic driver can take 1GB, so removing older ones with Driver Store Explorer might save quite a lot. I also have 40GB partition with 28GB free (hibernation/pagefile disabled), Windows takes 8,7 GB
    Attached Thumbnails Attached Thumbnails Windows 10 unexplained os size fluctuations-capture_05102018_105856.jpg  
      My Computer


  Related Discussions
Our Sites
Site Links
About Us
Windows 10 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 10" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd
All times are GMT -5. The time now is 16:11.
Find Us

Windows 10 Forums