I have an external HD which used to be my TimeMachine drive. I got a different drive for that, so I want the original drive back as an external on my Windows box, but it has this random 200 MB partition labeled as EFI System Partition. How do I get rid of this?

  1. On the command prompt type diskpart and answer to any possible UAC prompt.
  2. On the new diskpart prompt, type list disk. Note the Disk ### column.
  3. Type, select disk ### (with

    being the disk you wish to delete. Usually the disk with partition 0 with a size of 200 MB)

    NOTE: The disk may not show the 200MB partition in the disk list in Diskpart even if it exists.
  4. Finish by typing, clean.
  5. Type exit to exit diskpart

Have fun!

  • 1
    Very good! Makes you wonder why this is provided through the UI. – Wayne Hartman Jan 20 '10 at 22:43
  • 5
    Since the question was on removing a single partition, it should be noted that the "clean" command removes all partition information from the disk, effectively rendering it a blank disk. – olafure Jan 30 '13 at 21:13

Use DBAN to nuke all partitions on the drive (version 2 supports USB) and then create a new partition using Windows Disk Management.

If necessary, backup important data, as everything will be deleted.

  • I don't know if I want to use that: DBAN will automatically and completely delete the contents of any hard disk that it can detect I have 4 other drives in this machine... – Daniel Huckstep Sep 26 '09 at 23:24
  • 2
    it CAN, but it will only delete the content of the drive you SELECT, big difference :) you may of course disable the internal drives in the BIOS or even disconnect them physically and only leave the USB drive connected and thus detectable, if it makes you feel safer, but this is not necessary. you will be presented with a choice of drives and then you select the USB HDD and let DBAN do its thing. – Molly7244 Sep 26 '09 at 23:58

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