So, I have a 8GB USB thumbrive I am trying to format so I can use all 8 (or 7.27 to be exact) GB in a single partition. The drive already has a 943 MB partition, which I figured I could extend to use the full 7.27 GB but this does not seem to be the case

New Volume Right Click

As you can see, the Extend volume option is greyed out.

Also notice the Delete volume is greyed out..

If I right click on the 6.35 GB volume, which is currently unallocated I get the following unallocated volume

All of the options are greyed out on the Unallocated volume!

What tool can I use to remove the existing partition and create a new partition that uses the entire 7.27 GB in a single volume?

3 Answers 3


Windows will not let you partition removeable storage devices. You must delete all of the partitions and make a new, full size one outside of Windows. I recommend the GParted Live CD.

  • 2
    That's not entirely true; it will not let you create more than a single partition on removable storage devices. And the the 'Disk Management' GUI will not let you delete partitions from removable storage to "prevent inadvertent data loss". Mar 18, 2013 at 19:22

Have you tried using diskpart?

Specifically, in a cmd.exe window, running the following commands will erase and reformat your USB drive:

> diskpart.exe
    list disk                 'This will list your disk drives, 
                              ' note the number of your USB drive
    select disk #             'Replace # here with the number from above
    clean                     'This removes all partitions
    create partition primary
    select partition 1
    format fs=NTFS QUICK
    assign                    'This assigns it a drive letter

I had a USB drive that had been partitioned as a boot drive, but I needed to use it for normal storage again. I also could not re-partition/format using Disk Management (Start->Run->compmgmt.msc->Storage->Disk Management); it was greyed out for me too. Using DISKPART got me most of the way. Here's what I did:

  1. Click Start button then typed Command Prompt and right clicked and selected "Run as administrator". The Command Prompt (a.k.a DOS prompt for us old people) will appear.
  2. Type in diskpart.exe. You'll notice that you loose the "c:\" and you just see "DISKPART>" because this is an actual command line program. All the commands available in DISKPART can be viewed by typing in help
  3. list disk will list all the disks currently on your system, even ones that are not mounted. They'll show up as "Disk 1", "Disk 2" etc, with corresponding sizes. If you have a few different USB drives inserted with similar sizes, I suggest you only leave in the one you want to change, so you KNOW which Disk to choose on the next step.
  4. select disk # in my simple scenario, it was "select disk 1" You should see "Disk 1 is now the selected disk.". Disk 0 will most likely be your C Drive. Be SURE you've selected the disk you want to repartition.
  5. clean This will delete all the partitions.

For me that's all I needed. I was able to use create a partition and reformat after that using Disk Management, although I had to NOT use the "Quick Format" option.


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