How do I format and partition my new external hard disk?

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Summary: Partitioning and formatting a new disk, internal or external, is often not needed but it's easy to do using Windows built-in disk manager.

Well, to begin with, you may not need to. Most come pre-formatted as a single partition.

But if it didn't, or if you don't like the default setup, changing it is easy. And of course you'll want to do this before you load that disk up with data.

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As I said, most external hard drives come ready to use. Just plug 'em in, let Windows discover it, and *poof* there's another drive on your system ready to use.

Most will come pre-configured as a single unlabelled partition using the FAT32 filesystem.

If that's what you have, and if that's what you want, you can stop reading now, since you're done. You need do nothing more.

If you want to change what you have, the tools you need to do so are already right there in Windows.

Start by right clicking on My Computer and then clicking on Manage. In the resulting application window, click on Disk Management in the left hand pane. You should see something similar to this:

At the top you'll see all the logical disks on your system listed alphabetically by label by default. Below that you'll see a graphical representation of all the physical disk drives known to your system. If a physical drive has more than one partition those partitions will be shown together on the single physical drive.

In this example, my drive "E:" is an external USB drive. It happens to be my backup drive where nightly backups are stored.

Remove the Existing Partition

Let's assume for a moment that I'm unhappy with the current configuration of the partitions on my external drive and want to change it. My first step would be to remove the existing partition.

You need to right click on the drive in the lower pane, and you should see this menu:

Click on Delete Partition

The representation of the drive should change from "Healthy" to "Unallocated".

Partition The Drive

Right click on the drive again, and the option that was once "Delete Partition" is now "New Partition". Click on that to set up your new partition.

You'll then be asked to select "Primary" or "Extended" partition. Primary is sufficient unless you plan to put more than 4 partitions on this hard disk. You'll then also be asked how much of the space to allocate for the new partition you're creating.

Typically, I recommend simply allocating the entire space to a single partition. You can, if you like, allocate less than the maximum space to the partition you're creating now so that you have room for additional partitions on the same hard disk. Remember that each partition, once formatted, will appear as its own logical disk (C:, D:, E: and so on.)

You'll then be asked about formatting, which I'll cover below.

Once you've formatted the new partition, it'll appear as "Healthy", and any leftover space will continue to display "Unallocated". You can then repeat this partitioning process on that unallocated space until your entire drive has been allocated.

Format Your Drive

Assuming that partitioning has been performed above, or you don't want to change the partitioning of your drive, the next thing to change would be the format of the drive.

Right click on the drive that you wish to format, click on the Format item, press OK on the dire warning, and you'll get a dialog similar to this:

Let's look at each of those options:

• Volume Label - is the name that will appear when the logical disk is displayed in Windows Explorer, in File selection dialog boxes and in other situations. It's a convenient way to identify disks by name rather than only by letter. The label is an attribute of the drive, so particularly on removable drives the label stays the same no matter what machine you plug it into, or what drive letter it gets assigned.

• File System - I recommend NTFS unless the drive is going to be used by older versions of Windows, or by non-Windows systems. There's debate as to whether NTFS is faster (I think it is), but it also supports additional security features like file permissions, and can typically make more efficient use of larger disks.

• Allocation unit size - can be left at "Default".

• Perform a Quick format - for the type of format we're doing here, I actually recommend leaving this unchecked. A quick format only writes the bare minimum of information to establish the disk's new configuration. If the disk has been in use for a while, that's fine and is what I typically recommend. However, when going through the effort of formatting a new disk I suggest using this opportunity to have the format process actually write the entire drive. It may take a while.

• Enable file and folder compression - I have mixed feelings about this. The overhead of compressing and decompressing files is no longer significant with today's processor speeds. Howeve,r I have concerns about data recovery if the disk ever experiences an issue. My concerns may not be valid, but ultimately, I never run with compression on any of my hard disks, preferring instead to compress the individual files as appropriate instead. So many file formats, like most audio and video files, are already compressed that the compression offered by the file system is often negligible. I leave this unchecked.

That's it. Press OK and after a period of time you'll have a formatted, ready-to-use disk.

A Word on Disk Partitioning Utilities

As you've seen, the process we used above to adjust the existing partitions on the hard disk involve deleting the entire contents of the disk, changing the partition structure, and then placing the disk back into service.

It may not have to be that way.

There are third party utilities such as Partition Magic or Acronis Disk Director that will allow you to resize partitions without first erasing the disk. Of course I still recommend a full backup of the disk you're about to modify first, but these can be useful utilities.

Here's why I'm not suggesting them: how often do you really repartition a disk?

In my mind it's much more common to do it once, and then leave the configuration alone. A change is typically so infrequent that the utilities - however good they are - often aren't worth the effort.

However, that's obviously a decision you can make on your own, since it's a classic time / money tradeoff.

But particularly for a new disk just being placed into service, there's no need for advanced management tools. Once it's empty, and while it's empty, it's a perfect time to perform any partitioning or formatting or the like using Windows own built-in tools.

Related:

• What is disk partitioning? Partitions are ways of treating a single hard disk as if it were many. We'll look at why, how and when you might want to partition your hard drive.

• Can I make my C: partition bigger by taking space from D:? Hard disks can be divided into multiple partitions, each showing up as a different drive. Changing the layout of partitions requires special tools.

• I can't format my hard drive - it keep telling me "volume is in use by another process" -- why? "Volume in use" when trying to format most commonly means you're trying to format and erase the entire disk that has Windows on it.

Article C3447 - July 17, 2008