Unless you're very new to computers, the chances are that at least once you lost a lot of work when a hard disk crashed. Getting data back from a dead disk can cost thousands of dollars, and may not work. Tech industry insider Marty Winston explains some of the trade-offs.

The cost of the drive is the smallest part of the cost of the loss when a disk crashes; the lost work can set you back days, weeks, even longer. Backing up your most critical files to an optical disc or spare hard drive can save a lot of hassles and a lot of work.

For many people these days, that hard drive is also the only copy of their irreplaceable personal photos.