After partition extend file system displays wrong disk size in Windows

Recently I was working on a VM that has some free space problems on the Exchange partition of a Windows 2008 SBS server. So I extend the hard disk in VMware and Windows. That’s easy….

I extended the Hard disk size in VMware. Then I extended the Disk size in the Disk Management tool. All without any problems. But when I was checking the disk size in the Windows Explorer the size was incorrect. The old size was still showing. This is not good!!


Screenshot of the hard disk size in VMware.


Screenshot of the disk size in Storage Manager.


Screenshot of the disk size in Windows Explorer.

The fix is simple, open an elevated command prompt and start DISKPART

List all volumes of the server.

DISKPART> list volume

Select the volume that has the wrong file system size. x is the ID of the effected volume.

DISKPART> select volume [x]

Extend the file system

DISKPART> extend filesystem

Screenshot of the Diskpart commands.

If all went well diskpart fixes the size of the file system.

Go to the Explorer and the correct disk size is shown. Problem solved.

Screenshot of the corrected disk size in Windows Explorer.

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The information in this article is provided “AS IS” with no warranties, and confers no rights. This article does not represent the thoughts, intentions, plans or strategies of my employer. It is solely my opinion.


Marco works for ViaData as a Senior Technical Consultant. He has over 15 years experience as a system engineer and consultant, specialized in virtualization. VMware VCP4, VCP5-DC & VCP5-DT. VMware vExpert 2013, 2014,2015 & 2016. Microsoft MCSE & MCITP Enterprise Administrator. Veeam VMSP, VMTSP & VMCE.


  1. Bill Johnson

    Thanks…this was perfect. Had trouble finding a solution, but this worked.

  2. Happy guy

    Thank you very much! Was a bit nervious when i got that trouble, but after your advices in this article all is fixed!

  3. MicrosoftFrustrated

    Did you dismount your exchange databases before running diskpart or were they operational? This is happening to me on my drive that my mailbox databases reside on.

  4. I didn’t dismount the Exchange database.

  5. Schneilzel

    Reproduce the steps but I get this message:

    The volume you have selected may not be extended.
    PLease select another volume and try again.

    The volume is disck C:

  6. L.murali varma

    thanks a lot sir
    it really worked
    every can try it

  7. Wolfgang

    Thanks a lot for this article and the solution. You saved my day 🙂 Worked perfectly on a Windows Server 2k8 r2 after the GUI method of extending disk failed.

  8. J. Lauer

    This was a quick and easy fix. Thank you for posting.

  9. P. Kuhne

    Great fix, didn’t now about the “filesystem” syntax.

  10. Thomas Senn

    You made my day! Did work like a charm …

  11. Ty i had the same pb after using the free cloning partition tool “Renee”. The cloned partition did take all the size, but the filesystem did not. Ty again!

  12. steve bell

    worked great. thank you very much.

  13. Dennis

    Easy solution. Thanks!

  14. Lafufy

    Thanks! it worked like a charm. no need to reboot the fileserver now 🙂

  15. Aj

    Thank you. This fixed no problem not issues!


  16. Adrian

    Gracias me salvo la vida ^_^

  17. Henrik

    Perfect, fixed my problem

  18. S

    I tried, but this didn’t work for me. I went into VMware and extended it by another 1gb and everything resolved itself. Very strange issue.

  19. suru

    Thanks yr
    Your solution is perfectly explained. It worked for me:)

  20. Shushanth


  21. Calvin C.

    That helped! Thank you!

  22. Bob R.

    Thanks. This is exactly what I needed!

  23. Fredianelli, Alexandre

    Thanks a lot Marco!
    Solved my problem!
    Happy New Year from Brasil!

  24. This worked perfectly, thanks!

  25. Thank you this is a very helpful solution, all the other results said to just use “extend” even though in the case of VMs like ours the space is allocated, just not reported correctly by the partition in Windows Explorer.

  26. fish

    thanks for this articel! fixed my problem!

  27. PeteA

    Thank you!
    Much appreciated that you shared this!

  28. Keke

    Thank you. Same Problem, same solution.

  29. Mostafa

    It’s great..

  30. Fixed after a partition program crashed whilst resizing.

  31. This got me close, but in my case a default quota on the disk caused Diskpart to fail. Once I disabled the soft quota then running this diskpart command fixed my issue. Full details are here:

  32. partitiondude

    You absolute legend!! Thank you very much. I was searching high and low trying to use all sorts of supposedly wonderful partition tools to solve this and it was so simple!

  33. Satish

    Good one..Really came in handy when I also faced this issue on a Exchange server

  34. Jan-Willem van der Heijden

    Thanks! I believe the Disk Administration tool should have done this, so I wouldn’t need DiskPart for the extra nudge, but it worked so I’m happy 🙂

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