Chidi Okwara asked why one would choose to partition a hard drive
Partitions split one physical drive into multiple virtual drives. Each one uses an assigned piece of physical real estate on the media, and is treated by the operating system as a separate drive with its own drive letter.
Technically, every drive is already partitioned. A physical drive needs a partition to hold files. And if you bought your PC with Windows pre-installed, it probably already has two or three partitions. Only one of them, C:--which fills almost the entire physical drive--is for your regular use. The others, all of which are quite small, are for maintenance and recovery purposes.
So why would you want to make additional partitions? It's not like making folders. Creating and resizing partitions is a hassle.
One reason is to have multiple operating systems. If you want to run two versions of Windows, or Windows and Linux, partitions help separate the environments.
Another reason, and the reason why I've partitioned my drive, is to separate system and data for backup purposes. You leave Windows and your various programs on the original partition, C:. But you move your libraries (Documents, Pictures, Music, and Video) to the new partition, D:. In most cases, D: will be the larger partition.
Why bother? The only way to reliably back up your Windows environment is to create an image of your C: drive, along with those small partitions that came with the PC. But that image file will be very large and ungainly if it also includes your libraries. This way, the image--which you only need to back up two or three times a year--will be large but manageable.
Then you can use a simple file backup program to take care of your libraries on D:. That's a chore you need to do every day, so the simpler, the better.
You should also read my instructions on how to partition a drive.
Sign up for Computerworld eNewsletters.