It's most peoples worst computing nightmare. You wake up in the 
morning, flip on the computer, and it doesn't boot. Sometimes the 
problem rears its ugly head as a horrific clacking noise. Other 
times it simply gives a read error.

At this point, most people panic. The first thing you wonder is 
whether or not the data is recoverable. There is no universal 
answer to this. In some cases, a simple scan with some data 
recovery software is all that it takes to retrieve the contents 
of the drive. In other cases, if you want it badly enough, it 
will take thousands of dollars and a shipment of the drive to a 
clean lab where they will pull the platters inside of the drive 
and access them that way.

Now you're probably wondering if there's a way to prevent this 
from happening. Well, you're in luck. Getting a UPS 
(Uninterruptible Power Supply) is the very best and most 
effective way to prevent your data from pulling a disappearing 
act.

While it is not fool-proof, having something that regulates the 
electricity flowing into your computer can reduce the risk of a 
drive failure by up to 70%. This figure goes up to around 90% if 
the computer is being used while in an electrical storm. (My 
computer repair business always gets a little boost after a 
thunderstorm, courtesy of the lightning wreaking havoc on 
people's hard drives.)

Don't just run out and get any UPS. You want to get an 
intelligent one. The "intelligent" UPS will regulate the power 
without having to hit the battery every time the voltage takes a 
dip which greatly improves battery longevity. They also include 
options to hook the power supply up to your computer via a serial 
or USB port so you can monitor what the power is doing. This also 
gives the option to allow for a soft shut-down if the power goes 
out and you are away from your desk.

You can get an Uninterruptible Power Supply at most computer 
stores. Best Buy carries a fairly wide selection of them.

As for brands, I've personally used APC with much success. Opti-
UPS is another excellent brand. In fact, I have an Opti that is 6 
years old and still works fine, although the batteries now have 
no life to them. (That's to be expected. Rechargeable batteries 
only last so long)

Now that you know of the importance of a UPS I would strongly 
encourage you to invest in one. It is far better to spend $100 
now on some preventative maintenance than having to spend much 
more later on data recovery. 

Kevin Souter is a full time computer technician and operates a 
computer repair site, as well as a free spyware removal site.

http://www.TweaksForGeeks.com has articles and tutorials on all
sorts of computer problems from internet issues to hardware
defects, for the novice and the expert.
http://www.EradicateSpyware.net has been set up to teach you how 
to remove annoying Spyware / Adware / Malware from your computer.