Utilities are like a box of chocolates; you never quite know what you're going to get, but it's a sure bet you'll need at least one.

As more people purchase personal computers, and invariably encounter difficulties, the utilities software market is becoming as cluttered as a fragmented hard drive. According to PC Data in Reston, Virginia, system utility software sales rose from over $152 million in 1993 to more than $353 million in 1996, with over 300 utility titles on the market. We've sifted through this assortment of applications for you and emerged with some of the most popular and well-respected utilities on the market.

Norton Utilities, introduced in 1982, has long been considered the best all-around utility software package. Whether you use Mac or Windows, Norton Utilities is the most comprehensive package you can get. The latest Windows version ($79) features the system genie that allows users to customize Windows. If you've been using Norton Utilities for years and have recently upgraded to Windows 95, you'll be pleased with the new CrashGuard and Anti-Freeze programs, which guard against crashes and application lock-ups. The latest Mac version ($99) comes with a new Apple Guide that includes step-by-step instructions on how to use each utility. If you're using anything less than a PowerMac, you won't be able to take advantage of all of the new features. Norton, as well as all other Symantec utility packages, comes with live update in which you can access upgrades and patches via the Internet. Promoted as the package for all PC users, Norton Utilities really isn't for novices. You should at least know your way around Windows and something about file management before investing in it.

When it comes to diagnostic software, Quarterdeck's WINProbe95 ($49.95) is promoted as the Swiss army knife of utilities. WINProbe's minimum system requirements are for a 386 DX with only 8 megs of RAM. However, on our first test, despite its CrashShield, WINProbe crashed a 150mhz Pentium with 24 megs of RAM. On a second machine (with 48 megs of RAM), WINProbe worked well. Its Status Panel, which teaks like a stereo equalizer, provides real-time information about your system, such as the amount of RAM or disk space available. WINProbe's advanced diagnostics options include running noninteractive, stress and custom tests. Our favorite feature was the Registry Guru, which helps you manage the registry, the database used by Windows 95, to hold configuration information about your system. With hard drives topping 3 gigabytes and more peripherals being added to computers these days, cleaning up the registry is a must.

Cybermedia's First Aid 97 ($39.95) is simpler and probably better suited for beginners. You can access all its components from one screen and get reports on nearly every function you carry out. The program effectively finds problems with both Windows 95 32-bit and Windows 3.x 16-bit applications. Through its hardware troubleshooter, it detected a problem with a scanner's configuration that had plagued this writer for months. Although the program couldn't offer a specific fix, it at least identified the problem, which went a long way toward finding a solution.

Like most diagnostic software, First Aid 97 features a backup function that allows you to retrieve deleted data, with options for an automatic or manual fix. Some of its tests, such as Speaker Check, are somewhat superficial and could easily be done by the user. But others, such as the Plug 'n Play peripherals checkup, can help you weed out potential problems that could interfere with productivity. First Aid 97 also includes a scaled down version of Oil Change, the popular application that uses the Internet to search for and automatically install software upgrades and patches. In addition, a new-and-improved 98 version will be on the shelves this fall.

For the PC novice, Symantec's Healthy PC for Handy Man for Windows 95 ($29) and PC Handy Man for Windows 95 ($49.95) offer great ways to fine-rune your system without intimidation Healthy PC has a small-scale anti-virus program, hard drive check and defragmentation abilities. Its push-button interface makes it a cinch to use. PC Handyman has the same CrashGuard and Anti-Freeze protection as the meatier Norton Utilities, but its diagnostic abilities lack the depth of First Aid 97 and WINProbe 95.

For the more seasoned computer user, McAfee's PC Medic 97 ($29) does a thorough diagnosis, even more so than First Aid 97. But, unlike First Aid, it doesn't allow you to do group fixes. This makes PC maintenance as tedious as doing your own automotive oil change.

Among uninstall programs--which help you dean up your hard drives--Cybermedia's Uninstaller and Quarterdeck's CleanSweep and Remove It (all three list for $39.95) dominate the market. The most efficient is Uninstaller, which has a SmartLinks function that allows you to safely remove applications without removing required files and can also clean out Internet-related junk files. Our favorite Uninstaller function allows users to move any application to any other drive, folder or computer with all links intact. Like First Aid, Uninstaller updates itself automatically through Oil Change.

CleanSweep runs a close second to Uninstaller. This program has a user-friendly interface and easily finds and removes low usage, duplicate and redundant files. CleanSweep's wizards buttons make for easy navigation. Watch it, though; those same wizards might cause wanted files to disappear if you're not careful. To be safe, run CleanSweep's backup feature, SafetySweep, which guards against accidental file deletions. Remove It also manufactured through Quarterdeck, is not as efficient as CleanSweep or Uninstaller. It seems designed with more experienced users in mind. In our test, it crashed twice, once giving us a "fatal" error message. After the second crash, we decided to remove Remove It.

Quarterdeck's Essential Utilities 97 ($99) includes Remove-It, Fix-It, Partition-It and Zip-It. This package's best asset is Zip It, a great compression companion to anyone who routinely downloads files. Fix-It detected the s e scanner problem as First Aid 97 and offered the same solution. But don't even think about running Partition-It unless you're knowledgeable about how your hard disk works. Mess with this application and it's time for a double dose of Excedrin.

No system should be without anti-virus protection. The two leaders in this category are Norton's AntiVirus ($69.95) and McAfee's VirusScan ($49). You won't go wrong with either of these, though VirusScan ran a little slower than Norton's Anti-virus in our test. Make sure you get updates for these applications via the Internet to protect yourself against new viruses.

Finally, Starfish's Internet Utilities 97 ($19.95), an Internet utilities program, works great as a bookmarker to index favorite sites, especially if you use Netscape or Internet Explorer browsers. It includes applications that manage file compression (ZIP) and transfer (FTP). Internet Utilities also offers users insights into why they aren't making connections to particular Web sites. It scored big brownie points when it led us to the Cnet site, which had new Hewlett-Packard Scanner drivers available for download, just the fix we were looking for.