How to Format an External Hard Drive or a Spare Hard Drive

If you need to format an external hard drive it is a lot easier than formatting a hard drive that is being used to house your main Windows operating system. Your external hard drive might be an old hard drive that you have placed into an external hard drive case for storage purposes, and you now need to format it.

To format an external hard drive it must be attached to a computer in one way or another. They are very easy to connect to your computer now days and most of them use a USB plug and possibly a power cord. This article can apply to formatting an external hard drive, formatting a spare hard drive, or formatting any hard drive that you place into an external hard drive case. It can also show you how to format a USB flash drive. This article is not about how to format a computer with a hard drive that has the Windows operating system installed on it. That is a different story. Please be clear that this article is about how to format an external hard drive.

Reasons why you would want to format an external hard drive

  • To clean the hard drive of all previous information and start a fresh. You might buy a an external hard drive at a garage sale and it could be full of files that you do not want. It is recommended that you format the external hard drive, especially if you don’t know the person who you purchased from.
  • To recycle an old hard drive to use for storage. When you have put this old hard drive into an external case, this is definitely when you want to format an external hard drive
  • To get rid of corrupted files or viruses. If you think that the hard drive in your external hard drive has problems or maybe viruses they can be transported to your actual computer. This is why you should format your external hard drive if you are using it to connect to your computer. This will keep your computer safe from anything that was stored on that external hard drive.

If your hard drive is not installed anywhere?

Once your spare hard drive is installed in some way, it can be formatted from Windows XP, Vista, or Windows 7.

Format an external hard drive when it is connected to your computer

To format an external hard drive you will have to connect it to your computer. Hopefully your external hard drive does not hold an operating system and has just been used for storage device. To begin to format an external hard drive in Windows XP, Windows Vista, or Windows 7, you simply need to go to my computer on any of these versions of Windows.

  1. Go to the start menu at the bottom left of your desktop.
  2. Choose My Computer for Windows XP or Computer for Windows Vista.
  3. Right click on the hard drive you want to format.
  4. Please double check that you have the right hard drive.
  5. Choose Format from the menu. All data will be lost. The hard drive will be like brand new.
  6. After choosing to format  you will be asked to reconfirm your decision.


When you decide to format an external hard drive or even a USB drive, doublecheck that you are formatting the right drive. It would be a disaster if you accidentally had something plugged into your computer and formatted the wrong drive.

Watch this video to see how to format your spare hard drive.

Notes on how to format an external hard drive:

  • You can create your own external hard drive by placing a hard drive into an external case.
  • Now days everyone has an external hard drive for backup purposes and to aid with their computer maintenance.

Learning how to format an external hard drive is very easy after you have connected this device to your computer.


  1. panduranga chandrakant mohite says

    hello i am
    P. C. MOHITE. | Member Design [W/R]

    Acually problem is when i insert windows xp format disk and after some perocess i pressed C ( create) and computer search privious version of xp and and this process does not stopped. actually privious version does not found to computer. what problem

    so support for that. thanks you

  2. david davis says

    @Robert H Mercer:
    hey, robert. i read your post about your problem and it sounded very similar to a problem i had. 1 week ago i installed a new 250 hd to my 80 hd but could not format it. after reading your post i decided to delete partion and it worked! thanks for your information!

  3. Robert H Mercer says

    Believe it or not I found a solution, finally. After having almost given up hope I tried once again with the Disk Manager in computer management. Noticed [who’s been asleep then?] that one of the menu options of right-click is “delete partition”. Didn’t think it would do any good but lo, it deleted the damned partition, thus allowing me to format the drive. Good ol’ MS, always have to do things the hard way!

  4. Eric says

    You are correct. Windows will not delete files it believes are system files. You need to delete them off the secondary drive before windows loads up. I use a win98 boot disk and then the fdisk utility at the dos prompt. Hope that helps.

  5. Robert H Mercer says

    Not so! I have a hard drive on which I had Windows 7 32 bit. I installed Windows 7 64 bit on another drive for convenience as I did not want to over-write some of the programs. Now, apart from deleting all NON-SYSTEM files I am unable to format the hard drive [nor delete windows files] although it has no programs in use. The system boots using the 64 bit HDD and there has been no way to format the old 32bit HDD. I have tried external programs but so far even these are unable to format. The command prompt also fails in allowing it. I believe the problem is that Windows of whatever flavour sees that there are system files on the drive and therefore refuses to format – believing it will stop the system from working. Shows just how stupid Windows really is!!

  6. Mitz says

    If the folder is not in use and on a spare hard drive then it should be ok to format it.