To help readers follow the instructions in this article, we use two different typefaces.

Boldface type is used to identify the names of icons, agendas and URLs.

Sans serif type indicates commands and instructions that users should type into the computer and the names of files.

Ink-jet printers have several negative features, however. While their initial cost is low (as little as $100), they gobble up ink at a prodigious rate. As a result, each printed page costs as much as five cents—and that’s just for the ink. A laser printer, on the other hand, while initially more expensive, generates each page at a tiny fraction of a cent. In addition, most laser models print far faster than ink-jet models, and the printing quality is generally far superior.

So maybe you can compromise and have the best of both worlds. Buy one color ink-jet printer for those few times you want to print in color and get laser models for the rest of your needs.

Until recently, the least expensive black-and-white laser printer cost more than $400, but Samsung just introduced a seven-page-per-minute model (the ML-1210) with a $199 price tag. It appears to be the lowest-priced laser model on the market. You may want to check it out.

Q. I know I’m suppose to defrag my hard drive every now and then so it runs more efficiently. But every time I start a defrag, the function runs for a few minutes, stops and then starts all over again. I also get a message that says, “Drive contents changed.” I even once let it run overnight, and when I returned to the office the next morning, it was still trying to finish the job. What can I do?

A. Let me first congratulate you for even trying to defrag your hard drive. Defragging is like flossing after every meal: We know we should for good dental hygiene, but most people can’t be bothered. And that’s too bad because failing to defrag a computer regularly makes the computer drag—running slower and slower as time goes on.

Before I tell you how to overcome your problem, which isn’t unique, I’d like to explain what defragging is and why it’s important to do on a regular basis.

Defrag is short for defragmentation. Every file on a hard disk (or any storage device) is made up of tiny bits of data, and each time a file is saved, many of the bits get scattered to different parts of the disk, settling in the nearest vacant space. Thus, bits of data for a single file may be widely separated. Fortunately, the computer keeps track of each bit’s location, and when you call up a file, it gathers them all together.

But with each saving, the component bits get scattered more widely, and the computer has to work harder each time to locate the various bits and then reassemble them.

That’s where defrag comes in. When a tool that’s built into Windows, called a Disk Defragmenter, is evoked, it scans the hard drive, locates all the scattered bits and repositions them so all the bits of each file are situated as close to each other as possible. Defragging is a never-ending job—like flossing your teeth. The more you use a computer, the more frequently you need to defrag.

For most machines, a weekly defrag is sufficient. While you can launch the defrag tool manually, Windows comes with scheduling tools that let you automate the event; most people schedule it for after-office hours.

You’ll find the defrag tools and two maintenance-scheduling tools by clicking on Start, Programs, Accessories, System Tools.

Now, to answer your question about the application stalling and restarting. I would guess that defrag stalls in your computer because, in all likelihood, you have some application intermittently running in the background, and each time it stops, its data get scattered. Imagine trying to line up a bunch of hyperactive kids by height: It’s like trying to load frogs in a wheelbarrow. And each time the position of the data changes, defrag senses that and has to stop and start all over again.

To keep the data from scattering, you have to stop the program from starting. But you don’t want to permanently stop it because it could be an antivirus program or some other vital application.

The easiest way to temporarily stop it is to use what’s called a three-finger reboot or a hot reboot: You do this by holding down the Ctrl and Alt keys simultaneously and then pressing the Delete key. But be careful—do this only once. If you do it twice, your computer will reboot.

What you want to do by commanding the first step of the hot reboot is to evoke a Close Program screen that lists all the programs running in the background. By highlighting each application and then clicking on the End Task—one after the other—you can temporarily halt those apps from running. Be careful not to press the Shut Down key; that will reboot the computer. Also, never close two programs in the Close Program list: Explorer and Systray.

To do that, highlight the areas you want to hide, right-click and then click on Format Cells, bringing up this screen:

If you want to make the change permanent, go to Start, Settings, Control Panel, System. Click on the Device Manager tab and press the (+) symbol next to CD and right-click on the CD name that appears. Then either click on Properties or right-click again and select Properties. Choose the Settings tab and remove the check mark next to Auto insert notification. The changes will take effect after a reboot.

—The editors