How to partition external hard drive?

If you are using Windows XP then you can use DISKPART utility, which is the replacement of FDISK(Windows 95/98) utility. This is a command line disk management utility.
To run this utility, either open the console window and type DISKPART at the command prompt or use Run application.When you run this utility at the command prompt the prompt is changed to DISKPART prompt.

Here is the list of some useful diskpart commands.

1. Help - To see the help
2. Exit - To exit from the utility
3. List disk - To see the list of available hard disks
4. List Partition - To see the list of available partitions on the selected disk
5. Select Disk < disk number > - To select the hard disk for creating partitions
like - DISKPART> Select Disk 0
6. Create partition - To create partitions
7. Delete partition - To delete partitions
8. Assign letter=< Alphabate > - To assign letter to the partition
like -
DISKPART>list disk
DISKPART>select disk 1
DISKPART>list partition
DISKPART>select partition 1
DISKPART>assign letter=D

And there are many more command that you can check with help command.

Before going with this utility for partitioning you must decide how many partition of what size you want to create. For example I have 160GB external hard disk and I want to create 3 partitions of 50GB,50GB and 60GB.

First, I will connect my external hard disk with my PC.
Second, I launch diskpart utility at the command prompt and type in following commands at the diskpart prompt

in the same sequence.

1. DISKPART>list disk
2. DISKPART>select disk 1
3. DISKPART>create partition primary size=50000
4. DISKPART>create extended
5. DISKPART>create partition logical size=60000
6. DISKPART>create partition logical

In step 2 - disk 1 is my external hard disk
In step 3,5 - size is in MB
In step 6 - remaining size will be consumed

Note: After completing partitioning, disconnect external hard disk and re-connect it.

Now I will have to format these newly created partitions in order to use them for data storing.For that I use Window XP Disk Management utility.

Following are the step for accessing Disk Management utility.

1. Right click on My Computer icon on the desktop and select manage from the shortcut menu.
2. Now select Disk Management from the tree menu in the Computer Management window.