We've all had this nightmare. You turn on your functioning Windows/Linux PC, and all you get is a blank screen, or a message telling you that certain files are missing, or the kernel has panicked for some obscure reason. Nothing works, and you need the data on your machine. Yes, now's the time to whip out that trusty backup disk, and heave a sigh of relief that all the important stuff is backed up, right? Well, think again.
Most people do not back up on a daily, or even a weekly basis. Some people do not back up at all. Yes, there are uber-geeks with scripts that back up all their work on an hourly basis to offshore servers, but in a small business scenario, there are times when you have to get data off a computer that has crashed.