One of the most competitive areas in personal computer software is O utilities. That term once referred to simple little programs to make your computer work better, but now has come to include some big programs that do all kinds of things.

The most spectacular example in the IBM-compatible world is PC Tools Deluxe, $149 from Central Point Software. It regularly gets top marks in the trade press in the categories of DOS shells, file managers and desktop organizers. Such all-purpose programs used to be likened to a Swiss Army knife. But anything that could hold all the different devices in PC Tools would hardly be a pocket knife; it would be a toolshed. It comes on no fewer than six 5 1/4-inch disks.

PC Tools can back up your hard disk, retrieve lost data, view files created by 30 other programs, find files whose location you've forgotten, and move, copy, delete and sort files. It can edit text files with its own word processor, which includes a spell checker. It can unfragment the files stored on your hard disk, and includes "cache" software to speed access to the data you use most. There's also the ability to give your software password protection and to encrypt data so that only those intended can read it.

You can list your application software in a PC Tools menu and run it from within the program. Its "desktop manager" includes a word processor with spell checker, a database, a modem-communications program, an outliner, an appointment scheduler and four different calculators.

The programmers have done their best to make the package easy to use. It supports a mouse and lets you zip a block cursor around the screen, clicking in and out of the various functions. You can also use the mouse to manipulate windows on the screen and scroll through data, although the mouse does not control the cursor or scroll the screen within PC Tools' word processor. There is a set of drop-down menus at the top of the screen, easily used by either the mouse or keyboard.

PC Tools is versatile enough that some people might be able to make it the only program they use, but it's not intended as an integrated package of applications, such as Microsoft Works. Indeed, Works, which costs the same, is better for that purpose. It has not only a word processor, database, and communications program, but a spreadsheet as well. It also has a limited set of file-management tools.

So how does PC Tools stack up with the competition as a utility package with desktop tools? In terms of features, it beats everybody, but that doesn't make it the best. For one thing, PC Tools is unwieldy. Even without the full data-recovery and hard-disk backup included, it still takes up about 1.7 megabytes on a hard disk. The Norton Commander and Xtree Pro Gold, which provide similar file management and DOS shell capabilities, take up only about half that.

The program's file management is comprehensive, and it eliminates the onerous need to type in arcane file and path names when moving, copying or deleting files. It can perform these operation on individual files or groups of marked files. But the process is not as elegant as in, for example, the Norton Commander, where you can display the contents of two directories at once and move or copy files from one to the other by simply clicking on the move or copy function. In the Norton Commander, this opens a window on the screen with the full name of the other directory already displayed. All you do is click again.

In PC Tools, moving files requires you first to choose the "move" function. Then the program asks you to confirm that's what you want to do. It asks you to select a drive and re-reads the disk. Then you get to choose what directory on the drive. After all this, when one more pause might help avert error, it immediately executes the move. Too many steps.

The sheer size of the program makes it unsuitable for lap-top systems, such as the popular Toshiba 1000 series, many of which have no hard disk, but rely instead on the use of battery-backed extra memory ("hard RAM") for file storage. This can provide the functional equivalent of a one or two-megabyte hard disk, but nobody wants to use much of that for a package of utilities.

Lap-top users with no expansion memory need a small file manager that will consume little storage space and load quickly. The winner in this category has to be DIRMAGIC, written by the talented Michael Mefford, as a 1988 promotion giveaway for PC Computing Magazine. It displays either a directory "tree" or file list and permits a range of operations on single or marked sets of files. It consumes only 12K and you can get it free from user-group software libraries and bulletin boards.

Brit Hume is a contributor to the Washington Post Writers Group. He is chief ABC News White House correspondent and the founding editor of a computer newsletter.