Kate Murphy

If you use your laptop on your lap, or leave it plugged in all the time, you may well be cruising for what some experts call Picnic (Problem in Chair Not in Computer) or ID-10t (idiot) errors? computer problems caused by clueless users. Technical support professionals say these errors are responsible for at least half of all computer repairs. ?You?d be surprised how many people unknowingly damage their computers,? said Derek Meister, a technician for the Geek Squad, Best Buy?s repair and on-line support service. A classic mistake, Meister said, is using a laptop on your lap. Despite the name, a laptop should be operated on a flat and firm surface so that it rests on the four little nubs usually found on the base. A lap desk or even a large enough book will suffice. The point is to allow air to circulate around the machine.

Letting a laptop rest on your thighs?or worse, sink into a cushy comforter?prevents internal heat from radiating outward and can block air intake vents. This causes overheating, a major cause of component failure in computers. Using a laptop on a less-than-flat surface can also put the hard drive at an awkward angle, which can also cause damage. Speaking of the hard drive, don?t walk around with your laptop while the hard drive is active, because its actuator arm, which skitters over the surface reading or saving data, could bump into the drive?s fragile and finicky magnetic memory material. Many modern laptops have gyroscopes that shut down the hard drive when they sense movement, but that sometimes doesn?t happen fast enough to prevent harm.

?A lot of people close the lid on their laptop and throw it in their case without making sure the hard drive has shut down completely,? said Chris Kramer, director of technical support for Micro Center, a chain of 23 computer and electronics stores that has its headquarters in Hilliard, Ohio, a suburb of Columbus.

Kramer recommends manually putting a laptop in ?sleep? or ?hibernate? mode before closing the lid, instead of assuming that the hard drive will shut down automatically.

Another common user error is leaving a laptop plugged in all the time. ?A lot of people use their laptop as a desktop,? said Kevin Dane, executive director of product quality and reliability for Dell, the computer manufacturer. ?Leaving it plugged in all the time diminishes the battery life and degrades its performance.? Batteries, like muscles, atrophy if not exercised. Unplugging your laptop once in a while, say two to three times per week, is enough to keep the battery fit.

It?s also not a good idea to drain your battery completely and not recharge it for extended periods. Leaving a battery uncharged for a long time can cause a degradation of its chemicals.

Dust can also cause problems, though that is a bigger concern for stationary desktops, particularly if they are kept in areas with pets, smokers and carpeting.

Experts recommend cleaning out desktop and laptop computers at least once a year (every six months if the machine is in a really dusty environment) by taking them into repair centres for a thorough cleaning or by removing the outer case and using a gentle vacuum, compressed air, tweezers or cotton swabs to remove dust bunnies.

Never use standard household cleaners on or even near computers. The chemicals?and even the fumes?can seep into crevices and cause corrosion.

Picnic error can happen with software as well. While most people know not to download anything from a suspect source, repair technicians say that people frequently install an antivirus programme on new computers when one has been already loaded, usually by the manufacturer. Finally, most experts advise shutting down computers every few days to clear out the cache and short-term memory, set off routine system maintenance chores, and install and update software that might have been downloaded while the computer was in use. Moreover, restarting a computer often fixes mysterious glitches.