Customers are being overcharged for basic laptop repairs that should cost a fraction of the price, an investigation has found.
Which? placed simple software faults on a number of devices that should have cost less than £50 to fix, but were charged more than £100 by retailers in most cases.
Nine Windows laptops and 15 MacBooks were used as part of the study and taken to the Carphone Warehouse, Currys & PC World, Apple and some independent stores.
Currys & PC World only managed to repair one of six laptops correctly and charged £154 for it. A second laptop cost £169.99 to fix and had the wrong operating system installed, while the customer was told to buy a new hard drive they did not need.
Independent stores also charged above the necessary price, at £115 in one case and £200 for data recovery.
The Carphone Warehouse performed the best, charging £50, £20 and £24.99 for the repair of three Windows laptops, although one customer was advised to buy a £40 hard drive they did not need and another laptop had all data unnecessarily wiped to have a new operating system installed.
Apple charged nothing to repair four of six MacBooks, but did not try to fix the other two, which were older models.
"It's shocking that major high street retailers are failing consumers when faced with such basic repair issues and are charging people through the nose in the process," Which? editor Richard Headland said.
"We want to see improved staff training and repair procedures, as well as fair and consistent pricing so people can be confident in the services they receive."