Businesses make backing up simple. They buy big tape drives and back up absolutely everything all the time. When the inevitable hard drive collapse happens, the system administrator can restore the work in a matter of minutes.

For businesses, where every minute of downtime means dollars lost, that might make sense. But most individuals aren't willing to pay the money or take the time to back up everything all the time.

What should you back up?

For the rest of us, the essential rule of backing up is, "Make a copy of anything you can't otherwise replace." That means you make copies of all your personal data, such as documents, image and media files, email, financial data, saved games, and anything else that's important to you.

Don't make copies of Windows or your applications (unless you no longer have the master disks). If you copy the contents of a program folder, it usually doesn't operate the same as if it were installed. If you lose your hard drive, you'll have to take a few hours to rebuild it from the original program disks. That's not the end of the world. The main key is to have a recent copy of your precious data, so that you can restore it in the event that something does go wrong.

You'll want to back up some things every time you make changes. For example: I make a copy of my Quicken data every time I balance the checkbook. Other things can be backed up weekly or monthly. I'd strongly recommend backing up all your data at least weekly and saving a copy of that backup offsite. If you can't get to it weekly, then religiously try to do it at least once a month.

Keep files in one folder

You should have one folder where you store all your documents. Mac users will want to create one called Documents and will want to start getting in the habit of storing all their work inside this folder. Windows automatically makes a My Documents folder, and most Microsoft programs will automatically store their data inside this folder unless directed not to.

Not all programs automatically save documents to the My Documents folder. One critical exception is a program such as Intuit's Quicken. It stores data in its own program directory, unless you save it elsewhere. So if you're using Quicken, right now, before you forget, open Quicken and save a copy of your data to the My Documents folder. Once you do that, Quicken will continue to keep it there.

If you're religious about directing programs to store documents in the My Documents folder, backing up will be much simpler. Nearly everything you want to back up will be inside it. The key concept you should remember is that it's easier to back up one folder instead of having to hunt through your entire hard drive for files you can't live without when it comes time to back them up.

There are a few other things you might also want to back up.