So your computer files always have glitches in them, and you can't figure out why? Or your computer system constantly locks up -- for no apparent reason?
Maybe you have power problems, the kind caused by electrical disruptions that can play havoc with computer circuitry.
"Some of these disturbances are so minor that you and I don't see them, but your computer certainly does," said Margaret Rodenberg, vice president of sales and marketing for Viteq Corp., a Lanham-based maker of power protection equipment.
According to Ms. Rodenberg, it's those kinds of invisible power blips that can, if left unchecked, corrupt files, overheat hardware and cause premature power failures.
They come in the form of momentary reductions in power, sometimes called "sags." These sags can occur almost any time there is an extra drain on power lines, such as when an office computer or copier is turned on, Ms. Rodenberg said.
During the warm-up stage, office machines draw about 10 times more power than usual, she said.
Equally problematic are surges, when power peaks above normal. The latter may last only a few seconds, but they can be extremely damaging to sensitive electrical components.
A study of claims by Safeware, a major insurer of microcomputers, found that power surges were the second leading cause of personal computer losses in the United States after theft. In 1986, about $35 million worth of PCs were lost because of damage from surges, the study found.
Another power-related problem is lightning -- in the form of direct hits, blackouts and major power failures. According to the Safeware study, lightning accounted for about $14 million in PC losses in 1986.
Other power gremlins include "spikes" -- a short but powerful burst of electricity -- and "noise" -- a secondary electrical signal that tends to creep in on power lines.
But no matter what type of power aberration you're talking about, the result is often the same: Damage to delicate computer circuitry.
Fortunately for computer users, there are a variety of power protection devices available today, many of them costing as little as $50.
At the low end of the scale is the basic surge suppressor, a device that resembles an oversized extension cord with outlets. Computers are plugged into the surge protector, which is plugged into the wall socket.
In this configuration, the surge protector essentially acts like a sponge to absorb extra, unneeded power.
Surge protectors can be purchased for as little as $50, and they last indefinitely. These devices, however, will not protect against blackouts. For that, you need a standby power supply (SPS).
Essentially a box of batteries in a special housing, SPS equipment automatically turns on in the event of a power failure. SPS equipment is available for small stand-alone computers or whole networks.
SPS equipment starts at about $250 and goes up in price as the standby power supply increases.
The problem with an SPS box, however, is that there is a slight lag time between the time utility power goes out and the standby power kicks in. During that brief delay, costly computer equipment is vulnerable, Ms. Rodenberg said.
For people who don't want to take a risk -- even for a moment -- uninterruptible power supply (UPS) equipment may be the answer, she said.
UPS is a generic term to describe online power protection systems that work all the time, not just during emergencies or when disturbances in power supplies occur.
UPS equipment takes electrical power out of the socket and converts it into "perfect" power without surges, sags or noise. That purified power is fed directly into computers and office equipment connected to the UPS on a 24-hour basis.
In the event of a blackout or other catastrophic emergency, batteries contained within the UPS equipment will keep systems operating long enough to allow users to close out files in an orderly fashion and turn off the system without worrying about damage to online information, Ms. Rodenberg said.
The downside to UPS equipment is that it isn't cheap: The price of UPS boxes starts at about $1,500 and goes up from there.
And it doesn't last forever. Because UPS equipment operates constantly, it tends to wear out after a while. Longevity of UPS equipment varies. Some models last just a few years while others last considerably longer.
Viteq's patented line of UPS equipment, for example, will work for about 10 years before retooling may be necessary.
Not all companies need the protection that UPS offers, Ms. Rodenberg observed. But for those with an acute need to protect their data and online files, some sort of UPS system is probably a wise investment, she said.
"The thing you have to ask yourself is this: 'How critical is the information you're protecting, and what will it cost you if your system goes down?,' " she said.
If data aren't critical, one of the lower-priced power protection devices may suffice, she said.
"For somebody with a home computer who's just writing letters or somebody with a workstation doing light word-processing,SPS may be just fine," she said.
That view is shared by Bob Crum of Baltimore Sound, an audio dealer that sells power protection equipment. Baltimore Sound sells a line of surge protection devices made by Transtector Systems Inc. of Idaho whose prices start at about $120.
"UPS is best suited for somebody who cannot afford to have filed destroyed," Mr. Crum said. "But a lot of people just don't need that sort of protection."