Computers are among the most trouble prone products we track. Our annual product-reliability surveys have found that about 40 percent of laptops and 30 percent of desktops require repairs or replacement within three to four years of purchase. By comparison, fewer than 10 percent of digital cameras need repairs that soon.

In addition, because of the complexity of computers and their operating systems, owners need more hand-holding than with many other products. That’s why new computers have a period of free technical support.

The trouble is, like the factory warranty covering repairs, free tech support usually expires after a year. And support isn’t always effective. Our latest annual tech-support survey, conducted by the Consumer Reports National Research Center and drawing on readers’ experiences with 10,000 desktop and laptop computers, found that support solved problems for only about 60 percent of the respondents who used it. Apple’s support was much more successful, solving problems more than 80 percent of the time. But except for unlimited support in Apple stores, coverage runs for a fleeting 90 days after you buy your new Mac.

For more details about how the brands stack up on support, see our "Laptop tech support Ratings" and "Desktop tech support Ratings." (Both are available to subscribers only.)