Wallis Simpson, Duchess of Windsor, famously said, "You can never be too rich or too thin."

I would add, "You can never have too much storage."

With this in mind, home office or small-business owners can now buy internal hard drives at bargain basement prices. A terabyte-size drive from a quality manufacturer like Seagate or Western Digital can be purchased for as little as $60 from newegg.com, and 2 TB models start at around $80.

Why buy an extra drive?

Tony Stanford, a Honolulu-based small business IT consultant, has several reasons:

» An extra "slave" drive is a great insurance policy. It mirrors the contents of the primary hard drive, should the main drive crash, and makes data access speedier.

» An extra drive also can increase the overall life span of your computer by freeing up resources on your primary hard drive. You’ll need at least 15 percent to 20 percent of free space on your primary unit for best performance. Anything less, Tony points out, "the drive has to work harder to place data on the disk, which can lead to fragmentation." Left unchecked it can shorten your drive’s life span.

We looked at a 1 TB Barracuda drive from Seagate and a 2 TB Caviar Green from Western Digital.

WD has designed the Caviar for lower power consumption, hence the green moniker. (Seagate also has a Barracuda "green" series of drives.)

The install on both the Seagate and the WD went smoothly. Both units were very fast, quiet, cool-running and performed flawlessly. (For do-it-yourselfers, WD has a good video overview to get started: (www.facebook.com/video/video.php?v=239140200783).

What size drive to get?

According to Seagate spokesman Nathan Papadopulos, nowadays most standard Desktop PCs ship with 1 TB. (The price point, the difference between a 500-gig disk and Terrabyte — double the size — is only $20. If you have a ton of data as well as music, videos and games to store, for another $20 get a whopping 2 TB drive.)

For backup software we used Norton Ghost ($55 at newegg.com). Tony likes it as an internal backup solution for home offices and small-businesses clients. It’s easy to set up, it’s proven and works well in tandem with an extra drive.

The upshot: In all probability you will have a drive failure, virus or bad install at some point. A spare drive offers an extremely inexpensive insurance policy.