The most common cause of a messed-up computer is ... incompetent repair, according to some surveys. That's right, small problems turning into giant quagmires.

There's no shame in taking a machine into a Ft. Lauderdale or Miami computer repair shop. But how do you make the best decision as far as which one?

Here are four tips that should really help answer that ...

Look for longevity.Obvious as it sounds, business doors stay open for a reason. While many start-ups do high-quality work, a Ft. Lauderdale computer repair store that has been in business for five years or more is your best bet. Word gets around when a place does a shoddy job or tries to bilk its customers - an established organization almost certainly would not have survived with a seedy track record.

Get a guarantee. Any good Ft. Lauderdale, Boca Raton or Miami computer repair organization will guarantee its work. Unless warranty information appears right on the bill or on the firm's website, ask for a printed copy. Don't worry much if the warranty time period is relatively short. If a repair lasts for three months, it's likely the work was done right in the first place - as it should be!

Rely on reputation. Ask family members and friends if they can recommend a shop that has done good work for them. Check their opinions with a Google search, using the shop's name, to see what some unbiased (to you) people have said as well. Even the best Ft. Lauderdale computer repair facilities are not infallible, and are likely to garner negative comments. The key is to look at the big picture and establish whether a pattern of problems, or success, is what prevails.

Stay in charge. Literally. Pay with a credit card, even if you are not the type who likes to do so, because that will afford you a measure of power to challenge the charge later on if things aren't done to your satisfaction. Your credit card company gives you the right to dispute charges (or should, in any case), which you may not know because situations occur so infrequently in which you would need or want to. But you can and should take advantage of that powerful option when you can - and hedge the bets you make on computer services in any case.