Q I use a second hard drive to back up my primary one. Since hard disks are so inexpensive, I wonder why this method isn't more prevalent. Is there an inherent weakness in my solution?

A Backing up a hard drive to a second hard drive is easy and fast, but not carefree. You can't easily separate an internal hard drive from your computer, the way you can separate tape or other removable media. That means your backed-up data is not protected against power surges, fire, or theft. One way around this is to use one of those removable hard disk frames you can buy for around $30. They not only let you remove the second hard disk from your PC, but you can take the disk to another, similarly equipped PC.