Skip this article: (if you don't back up your computer): a few mouse clicks can save your data.

EXECUTIVE SUMMARY

* Two groups of files--programs and data-need to be backed up, and each requires different timing and a different method.

* One of the most powerful tools for copying everything is Norton Ghost, which can make a complete snapshot of your entire hard disk. If your computer fails because of an operating system problem, the backup of your operating system usually can revive it.

* Don't store backups on your main hard disk (usually your C:drive) or on any drive inside your computer. If your computer fails, you won't have access to it.

* One of the best places to store backups is an external hard " drive, which can be connected to your computer via an ultrafast Universal Serial Bus (USB) cable. Even if the computer should fail, the data on the external drive will be accessible--all you have to do is unplug the drive and plug it into another computer.

* Once you set up your backup programs, you're still not done. Test them often to be sure your system works.

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If you don't back up your computer regularly, this article is sure to make you very uncomfortable. However, I can promise you this: Your discomfort quotient will soar if your computer crashes or a file-eating virus destroys all your data. If you're still with me, congratulations--either because you do regularly perform backups and want to learn more about the process, or because you've decided this is the day to learn how to protect yourself with just a few mouse clicks.

WHAT TO BACK UP

You'll need to back up two groups of files, each requiring different timing and a different method: (1) your computer's operating system (probably Windows XP) and applications (programs such as Word and Excel) and (2) your data files.

The operating system and program files require special copying software because the computer probably will be using some parts of those applications during the backup process and thus they will not be accessible for copying; an application can not be restored if even just one of its files is missing. One of the most powerful tools for copying your entire hard disk is Norton Ghost (www.symantec.com), which costs about $70. Should your computer fail because of an operating system problem, a Ghost snapshot usually can revive it.

Although Ghost also can make frequent scheduled data backups, it's a lengthy process that slows your computer to a crawl. As a result most users make only occasional snapshots of the entire computer hard disk and use a different technique to back up data files that are frequently revised, deleted or changed. We'll describe this in more detail later. You should back up your data at least once a day or as soon as you finish working on a file you can't afford to lose.

WHERE TO PUT BACKUPS

Never store backups on your main hard disk (usually your C:\ drive) or on any auxiliary drive inside your computer. That may seem obvious but, as you'll see, it's actually one of the most common mistakes. The reason, of course, is that if your computer fails, you won't have access to any data in it. One of the best places to store backups is an external hard drive, which can be connected to your computer by an ultrafast Universal Serial Bus (USB) cable. If your computer crashes, all you have to do is unplug the drive and plug it into another computer and you will able to read or download everything,

Another reason external drives are so popular for storing backups is that when your computer is running fine, it instantly recognizes the external drive and treats it as if it were just another drive on the computer--with one important exception: the data remain accessible if the computer fails. Recognizing the popularity of external drives, hardware manufacturers have made them as small as a paperback book and given them storage capacity and speed that match or exceed most internal computer drives.

Obviously, the external drive should be large enough to store everything on your computer, plus a little extra. A 500-gigabyte (Gb) drive, which costs less than $400, can store whatever is on most internal disks several times over. For the convenience of users, some manufacturers even bundle backup software with their drives. The exhibit on page 43 lists some of the leading products.

External drives come in four generic types. The most common, and usually the least expensive, comes with no software or special button controls; it's just a hard drive that connects to your computer via a USB cable. The second type, for example, Western Digital's Dual Option Media Center or Seagate's Pushbutton Backup Drive, contains software that lets you program which files to back up and when, and comes with push buttons to launch the backup manually The third type--for example, the Maxtor Shared Storage Plus drive--is designed to back up several networked computers. It also contains software that provides a separate personal folder for each computer on the network.

The fourth type of external drive is based on new hard-disk technology that allows it to pack loads of data more densely The Western Digital Passport Drive, a flat model that holds 120 Gb of data and fits easily in the palm of your hand, is perfect for backing up files on a laptop while traveling. It contains no backup software, so you'll probably want to automate the drive with one of the products described later in this article.

SPEED AIDS THE IMPATIENT

There are several ways to conduct backups. The slowest is to copy every data file on your computer but many impatient users respond by backing up infrequently if at all. A faster method is to back up only files that are new or have been changed since the last operation. That typically takes from a few seconds to a minute, depending on the number of changes.

There's also another decision to make: whether to store backed-up files in their original format or use software to compress them. Compressed files take up less storage space, but the compressing action does take extra time, and there's a risk of not being able to successfully uncompress the files when you restore them. This is a particularly serious concern if you use a proprietary compressing format--so serious that knowledgeable users avoid proprietary compression programs altogether. Instead, they prefer software that uses WinZip (.zip), a nearly universal format that's built into Windows' Explorer, which makes it safe and easy to use.

A BACKUP STRATEGY

To further guarantee safety and efficiency, consider using two backup methods: Once a week or so perform a full backup of every data file using compression. Then, either daily or more frequently (as needed), trigger an incremental backup, a much faster uncompressed backup of any files that have been added or changed. An easy-to-use and relatively fast application that compresses either full or incremental backups is ZipBackup (www.zipbackup.com), which costs $40.

Another application, which can do full or incremental backups with or without compression, is SynchBackSE (www.2brightsparks.com). It also gives users the option of synchronizing the source and destination files, which is handy for those who travel and need their laptops to be synchronized with their office machine. It costs $25.

There are at least three good reasons to use two backup applications. The most important is that backup failure is not an option. If one of your applications fails or you accidentally program it incorrectly, you can fall back on the second application. The second reason is to provide a backup strategy. Say you use a compression program such as ZipBackup once a week or so to save all your data files; in other words, you purposely program it to take a compressed snapshot of all your files (not engaging the incremental option). All those zipped files, which take up relatively little room, constitute a historic record of all your data, including files that were subsequently deleted or changed. You'd be surprised how often you may need to look up an old file that has been edited or even deleted from your computer months or years ago.

The third reason has to do with convenience. If you frequently engage a program such as SynchBackSE to do only an incremental backup of files in their native formats, in effect you are quickly generating a series of real-time snapshots of your data. If a current file becomes corrupted or you accidentally change or erase it, a few clicks in the SynchBack up directory will restore it.

In short, both programs provide easy ways to create programmed buttons you can store on your desktop (see screenshot at left); a single click engages the backup of your choice.

OTHER OPTIONS

There are other places to store backups. While CDs and DVDs have large storage capacity, they are not as convenient as external drives. The backup data must be burned onto CDs and DVDs, and because their surfaces are subject to scratches, the data could be compromised. They also are subject to oxidization, with an expected lifetime of only about 10 years. Disks are used most often for permanent (if you can call 10 years permanent) storage rather than for frequent updating.

The new kids on the storage block are compact flash drives (commonly called memory sticks). Unlike hard-drive platters that are "read" by a sensing arm, memory sticks have no moving parts and are very rugged. Some users carry them in their pockets, or even hang them on a necklace. They still are a bit pricey and don't yet have the capacity of external drives, but as their use grows, prices will fall and capacity will rise. iPods use compact flash drives.

Although you can program any backup software product to copy all your Outlook e-mails and addresses, finding the huge outlook.pst file, which stores those data, can be a challenge. It's usually hidden deeply in the Documents and Settings directory. You can find it using Explorer's Search tool, but an easier way is to use Microsoft's new Outlook backup program, Personal Folders Backup Utility, which can back up your .pst file each time you close Outlook.

For more information go to http:// office.microsoft.com/en-us/assistance/HA010875321033.aspx.

Another option is to subscribe to a secure online service for a small monthly fee, which gives you the extra advantage of safety and also lets traveling laptop users back up via the Internet from any location. Services like Xdrive (www.xdrive.com) rent 5 Gb of storage for $10 a month.

TEST, TEST, TEST

Even after you set up your backup programs, don't assume they actually work. The only way to be sure is to test the system at least once a month. Believe me, you'll sleep better knowing your data are safely accessible. Now, aren't you glad you risked reading this article?

Simon Petravick, CPA, CIA, is an associate professor at Bradley University, Peoria, Ill. His e-mail address is [e-mail].

Exhibit External Storage Devices

                           Maxtor                  Seagate
                       Shared Storage             Pushbutton
Product                     Plus                    Backup

Price                    $300-$500                $197-$380

Storage                  200-500 Gb               200-400 Gb
capacity                                     500 Gb coming soon.

Interfaces         10/100 RJ-45 Ethernet;          USB 2.0;
                          USB 2.0                  Firewire

Included backup      Maxtor Quick Start         CMS BounceBack
software                  Software                 Express

Comments                  Backs up             Push of a button
                     multiple computers        triggers backup.
                        via router.

Web site               www.maxtor.com          www.seagate.com

                          Western                  Western
                      Digital Passport           Dual Option
Product                    Drive                 Media Center

Price                    $120-$230                $120-$280

Storage                  40-120 Gb                120-320 Gb
capacity

Interfaces                USB 2.0                  USB 2.0;
                                                   Firewire

Included backup             None               Dantz Retrospect
software                                           Express

Comments                Designed for        Drive has two buttons.
                     out-of-office use.         One launches a
                     Pocket-size drive        backup; the other
                   doesn't need external     configures daily or
                       power supply.           weekly backups.

Web site                www.wdc.com              www.wdc.com