After performing the “diskpart extend” command to merge two partitions the new partition will display in disk management however will not show the full capacity. This is a known problem if the command was run without sufficient system resources.
The partition size is extended, but the file system remains the original size when you extend an NTFS volume” – Unfortunately Microsoft have pulled the original “KB832316” (As of 2021) so there is limited information available. There are some references for diskpart here: KB325590

The following method of fixing this with the diskpart tool may work for some (but not others)

list volume
select volume X
extend filesystem

If like me you received the following error “Diskpart failed to extend the volume. Please make sure the volume is valid for extending” then there is a 99% this method will not work, in this case you can use the FSEXTEND.EXE tool, after burning around the net and looking at the following EE article it seems that getting hold of the tool is another problem. I resolved this by 45minutes of talking to Microsoft and getting a case open… but to avoid this I’ve uploaded the tool…

Trying to get FSEXTEND.EXE ?

How to Use:

The FSExtend tool really is a “one trick pony” if you try to get the switches required by the program it will simply return with “usage: fsextend.exe driveLetter” so you just need to perform the following:

DISKPART> select volume 1
DISKPART> extend filesystem
DiskPart successfully extended the file system on the volume.
Leaving DiskPart...

15 thoughts on “FSEXTEND.EXE (Diskpart)

  1. S Udayakumar

    This tool is really helpful and it also very rare tool which we cannot get it easily.

    Thanks a lot for your help….

    u r really sharing and njoying


  2. Nimesh Vatsa


  3. Dom Post author

    Haha, yeh took me a while to get hold of this! Annoying when you know it’s the tool you need but just can’t find it!

  4. Mark Page

    Jeeees. Yet another prime example of Microsoft incompetence.

    FSEXTEND.EXE saved my day. This is the last step of a huge process starting from taking an image of a 15 gig system partition and restoring onto a 150 gig RAID Mirror

    The server ran but only reported 15 gig system partition and i couldnt resize it in diskpart, disk manager or any other native or third party utility.

    Thanks man. Great Work.

  5. soorya

    Seems your knowledge is great.
    Can you pls. help me to get a command line tool to Shrink the partition without rebooting ?
    DiskPart doesn’t have Shrink command in WinXP.
    I need for WinXP.

    I have C:\, D:\ and E:\ (E:\ is logical and has space)
    I need to shrink E:\ to nSize and create F:\(logical).

    Thanks in advance….

  6. Dom Post author

    Dell have a tool called “extpart” which allows you to re-size the partition without a reboot (it doesn’t work on x64)
    You can download it from here: http://goo.gl/ga9VZ

  7. Matt

    You saved our bacon today! Windows 2000 server Diskpart does not recognise extend filesystem command. Thanks goodness for you!

  8. Martin Griffiths

    Thanks you so Much! been scratching my head for a while on this one

  9. Dom Post author

    FSExtend is a very simple program.
    Please see KB832316 on how to use it.

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