—Barbara Aslakson, St. Louis Park, Minn.
ANSWER: How long a backup drive will last depends on whether it’s a hard drive or a flash drive, and how much you use it.
Hard-drive failure is caused by wear and tear on its mechanical moving parts. In general, hard drives that are used regularly tend to fail in three to five years. Most external hard drives sold to consumers have two- or three-year warranties. But a backup drive that is used once every two weeks might last much longer.
Signs of an impending hard-drive failure include clicking or grinding noises. If you hear them, shut down the computer right away to minimize data loss.