I have previously urged you to "back up" important data on your computer's hard drive. But I think we need to step back and discuss just what we're talking about.

When you create a file -- a letter you write in Microsoft Word, for example -- that file is stored on your computer's hard drive until you delete it. The same thing happens with your Quicken checkbook, your family tree and your resume. Nearly every application you install creates data files on the hard drive.

Eventually, that hard drive is going to die. It may be sooner, it may be later, but someday it will thrash its last. That means the stuff you've stored there is gone, unless you hire an expensive data recovery service.

So the answer to all of this is to copy or "back up" your important files to another source. In the case of a word processing file, you'd hit SAVE to save it to your hard drive, then insert a floppy disk or ZIP disk and hit SAVE AS, select the removable disk drive and save the file again.

Then you store that disk someplace safe. In the case of really important files, such as a customer database, you should store one copy off-site (in case of a fire at your place of business) and rotate other disks in. For example, on Monday you'd use Disk 1, on Tuesday you would use Disk 2 and on Wednesday, Disk 3. On Thursday use Disk 1 again and so forth. That way you always have two backups.

There are affordable tape solutions out there, but tape in general has fallen out of favor for home users because it would take so many tapes to back up a whole drive; consumers won't sit around and swap them out. For most home and small-business users, re-writable CD-ROM drives (CD Burners, CD-RW) have become downright mandatory and very popular. You can back up your data (usually 540MB per CD), you can copy CDs, you can make your own music CDs, and they are a great place to archive data for a safety deposit box (thin counts). Re-writable CDs are very inexpensive, compared to tapes and bought in bulk are the cheapest data storage solution/per MB going. One of the newest solutions on the market are "Flash Drives" or "Thumb Drives." These tiny devices (about the size of your thumb) plug into the USB port. Some of these drives can hold as much as 1GB of information which is twice as much as a re-writable CD-ROM.

High-end users and corporations use high-capacity tape drives that hold 8 G of data and more, but price has kept those drives out of reach of most consumers.

What to do? Don't sweat a complete system back-up. You have the original CDs and disks of all of your software. Reinstalling stuff on a new drive would take a day or two, but you will live.

But if you lose all of your data, that's another kettle of dead fish. With ZIP drives and even larger Jazz drives so affordable, and with the advent of Rewritable CDs, there's no reason that all of your critical data will not be safe and sound every night. Many people buy a second hard drive and install it to use as a backup. You can also consider storing files on someone else's hard drive.

With so many solutions, you should be backing up your data files every week.