written by: Chris Hoffman•edited by: Simon Hill•updated: 5/21/2011
External hard drives require partitioning. And, just like internal hard drives, the Windows Disk Management partitioning utility can be used to create new partitions. If you don't have any unpartitioned space, you can shrink a partition or even delete one to make space.
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Hard Drive Partitioning Basics
Hard drive partitions separate a hard drive's storage space into multiple sections. Even if you don't want to divide your external hard drive's space and you want to use it as one big partition.
Some new external hard drives may not come with any partitions and need a partition created, or you may want to shrink an existing partition and create a new one. This guide covers partitioning an external hard driveusing the Disk Management utility on Microsoft Windows, included with every recent version of Windows, from Windows 2000 to Windows XP, Windows Vista, and Windows 7.
1. Make sure your external hard drive is plugged into your computer and its power is turned on.
2. Open the Computer Management utility by clicking "Start," then right-clicking "Computer" on the start menu and clicking "Manage."
3. Open the Disk Management utility by clicking "Disk Management" under the "Storage" header at the left side of the Computer Management window.
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Shrinking a Partition
If your external hard drive has no unpartitioned space shown at the bottom of the Disk Management window, you will need to shrink an existing partition to make some free space before creating a partition. You could also delete a partition, of course, by right-clicking it and selecting "Delete Volume." Be sure that you have no important data on this partition, the files on the partition will be lost
1. Shrink a partition on the external hard drive by right-clicking it, then clicking "Shrink Volume."
2. Type a new size for the partition into the "Enter the Amount of Space to Shrink in MB" box in the Shrink window. The size of the partition after shrinking must be less than or equal to the "Size of Available Shrink Space in MB" value, which is the amount of free space on your hard drive. If you shrink the partition by the maximum amount, you won't be able to write any more files to the partition unless you delete some files first.
3. Click the "Shrink" button at the bottom of the Shrink window.
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Creating a New Partition
1. Open the New Partition wizard by right-clicking in an area of free space on the external hard drive at the bottom of the Disk Management window, then clicking "New Partition."
2. Skip the "Welcome to the New Partition Wizard" window by clicking "Next."
3. Select the type of partition you want to create in the "Select Partition Type" window. If your external hard drive has three or fewer partitions on it, just click "Primary Partition," then click "Next."
Primary Partitions vs. Extended Partitions vs. Logical Drives: Hard drives support up to four primary partitions, and every partition after that must be a logical drive in an extended partition. However, an extended partition must be created in place of one of the four primary partitions for this to be the case. So, if you want five or more partitions on your external hard drive, first create an "Extended Partition," then go back through the wizard and create additional "Logical Drives."
4. Type the desired size of your partition into the "Partition Size in MB" box in the "Specify Partition Size" window, then click "Next." The size of the partition must be equal to or less than the "Maximum Disk Space in MB" value. If you only plan on creating this one partition, make the partition as big as possible, equal to the "Maximum Disk Space in MB" value.
5. Assign a drive letter to the partition in the "Assign Drive Letter or Path" window by clicking the box next to "Assign the Following Drive Letter," then click "Next."
6. Format the external hard drive's new partition in the "Format Partition" window. Type a name for your partition into the "Label" box, then click "Next."
NTFS vs. FAT32: You should leave the default file system as "NTFS." NTFS is a more modern file system than FAT32 and has many advantages. While compatibility with Linux was, in the past, a reason to choose FAT32 over NTFS, newer Linux distributions contain full, out-of-the-box support for writing to NTFS drives.
7. Verify the settings of your new external hard drive partition in the "Completing the New Partition Wizard" window, then create the new partition by clicking "Finish."