A new report from consumer organisation, Which?, investigated a number of high street IT repair services, and discovered a catalogue of failures, and shocking charges.
So what should you be wary of?
Which? took 24 laptops with simple faults to a number of repair services, including chains such as PC World/Currys, Carphone Warehouse, and Comet - as well as independents. In total, only 13 of them returned useable.
Not only was the lack of skill among the so-called experts alarming, but the charges varied dramatically too. The most expensive one charged the user £200 to replace the hard drive - which was unnecessary - and they failed to copy over the files at the same time, with potentially disastrous results. The average charge for the repairs came in at £86.
The investigation was carried out after a smaller one in 2011 revealed worrying failings. At that time, most of the services were able to reconnect two lose wires (although one suggested a new hard drive), but only two out of 12 were able perfectly solve a problem that the researchers had introduced with a piece of laptop software.
Which? pointed out: "Trust is a big part of the equation here. You're giving an expensive item, which likely holds many precious documents and photos, over to a complete stranger. I'd like to assume that these companies are treating such items with care and respect, but instead many problems are being left unfixed and data is going missing. These stores need step up to the plate and give their customers a much better repair service."
So what can you do?
It leaves computer users in a difficult position. So many of us rely on them heavily on them for work and for everything from entertainment to storing photographs. So when they go wrong we are all at sea.
There are a few things we can do. The first is to protect our computers against virus attacks - responsible for a good chunk of computer problems. Up-to-date virus software is a must for any user.
Second, it's worth understanding a few of the basics. Which? produces a repair top tips, which would be a good place to start.
Third, consider whether it's worth it. If it's an old model, which is nothing but trouble, then for little more than the cost of these repair services, you could invest in a new model, which will be far less disaster-prone.
Failing all of this, you will need an expert to help. It is worth trying to track one down before you hit a crisis. Ask around among your more tech savvy friends for their recommendations, read around the reviews and recommendations online. Then arm yourself with a phone number you'll have access to without needing your computer. That way, if the worst comes to the worst, you won't be left sticking a pin in a map and taking a chance.
10 of the biggest consumer rip-offs
Which? warns of failing IT repair services
Using a mobile phone to make and receive calls, send texts and browse the web while abroad can be extremely costly – especially if you are travelling outside the European Union (EU), where calls can cost up to 10 times as much as at home.
To avoid high charges, Carphone Warehouse suggests tourists ensure a data cap is in place, use applications to check data usage, turn off 'data roaming', avoid data-intensive applications such as Google Maps and YouTube and use wi-fi spots to update social networking sites.
Payment Protection Insurance (PPI) is supposed to help people to continue meeting their loan, mortgage or credit card repayments if they fall ill or lose their jobs. However, policies are often over-priced, riddled with exclusions and sold to people who could not make a claim if they needed to.
At one point, sale of this cover - which was often included automatically in loan repayments - was estimated to boost the banks' profits by up to £5 billion a year.
Now, though, consumers who were mis-sold PPI can fight back by complaining to the bank or lender concerned and taking their case to the Financial Ombudsman Service (08000 234567) should the response prove unsatisfactory.
It could be you, but let's face it, it probably won't be. In fact, buying a ticket for the Lotto only gives you a 1 in 13.9 million chance of winning the jackpot.
With odds like that, you would almost certainly be better off hanging on to your cash and saving it in a high-interest account.
No-frills airlines such as EasyJet may promote rock-bottom prices on their websites. But the overall fare you pay can be surprisingly high once extras such as luggage and credit card payment fees have been added - a process known as drip pricing.
Taking one piece of hold baggage on a return EasyJet flight, for example, adds close to £20 to the cost of your flight, while paying by credit card increases the price by a further £10.
It may therefore be worth comparing the total cost with that of a flight with a standard airline such as British Airways.
Cash advances, which include cash withdrawals, are generally charged at a much higher rate of interest than standard purchases.
While the average credit card interest rate is around 17%, a typical cash withdrawal of £500, for example, is charged at more than 26%.
What's more, as the interest accrues from the date of the transaction, rather than the next payment date, costs will mount up even if you clear your balance in full with your next payment.
Supermarkets such as Tesco and Asda often run promotions under which you can, for example, get three products for the price of two.
However, it is only worth taking advantage of these deals if you will actually use the products. Otherwise, you are simply buying for the sake of it, which is a waste of your hard-earned cash.
Buy a train ticket at the station on the day of travel and the price is likely to give you a shock - especially if you are travelling a long distance at a busy time of day.
However, you can cut the cost of train travel by 50% or more by going online and making the purchase beforehand - especially if you book 12 weeks in advance, which is when the cheapest tickets are on sale.
Other ways to reduce the price you pay include avoiding peak times and taking advantage of so-called carnet tickets, which allow you to buy, for example, 12 journeys for the price of 10.
Most High Street banks offer packaged accounts that come with monthly fees ranging from £6.50 up to as much as £40, with a typical account charging about £15 per month.
Various benefits, such as travel insurance and mobile phone insurance, are offered in return for this fee. But whether or not it is worth paying for them depends on your individual circumstances.