You need a video adapter and a monitor or display to complete your system. Numerous choices are available in this area, but the most important piece of advice I have to give is to choose a good monitor. The display is your main interface to the system and can be the cause of many hours of either pain or pleasure, depending on which monitor you choose.

I usually recommend a minimum of a 17'' CRT display these days (equivalent to a 15'' LCD display). Anything smaller can't acceptably display a 1,024x768 pixel resolution. If you opt for a 15'' or smaller CRT display, you might find that the maximum tolerable resolution is 800x600.

This might be confusing because many 15'' monitors are capable of displaying 1,024x768 resolution or even higher, but the characters and features are so small onscreen at that resolution that excessive eyestrain and headaches are often the result; the display often is blurry when a monitor is run at its maximum resolution.

If you spend a lot of time in front of your system and want to work in the higher screen resolutions, a 17'' CRT display should be considered mandatory. If you can afford it, I recommend a 19'' CRT display; they work even better at the higher resolutions and have come down in price considerably from previous years.

Look for CRT displays with lower dot-pitch (0.28dpi or less), which indicates the size and spacing of dots in the CRT mask. Lower means higher resolution and a clearer picture. If your desk space is limited and you can afford it, consider the wide variety of flat-screen LCD panels now available (a 15'' LCD panel is about equal in viewable area to a 17'' CRT).

In most cases, they attach to the normal VGA analog port, but the most current models work with the DVI connector available on some of the newest video cards. LCD panels are an excellent choice if you always use the native resolution (typically 1024x768 on 15'' displays or 1280x1024 on 17'' displays), but if you need to change resolutions (for previewing Web page designs or game playing), CRTs are better.

Your video card and monitor should be compatible in terms of refresh rate. The minimum refresh rate for a solid, nonflickering CRT display is 70Hz–72Hz (the higher, the better). If your new video card can display 16 million colors at a resolution of 1,024x768 and a refresh rate of 76Hz, but your monitor's maximum refresh rate at 1,024x768 is 56Hz, you can't use the video card to its maximum potential.

Configuring a video adapter to deliver signals the monitor can't support is one of the few software configuration processes that can physically damage the system hardware. Pushing a monitor beyond its capabilities can cause it irreparable harm. Note that LCD displays don't flicker, regardless of the refresh rate.

Video adapters in recent years have become standardized on the accelerated graphics port (AGP) interface, although many older systems used PCI-based video cards. You might need to use a PCI video card if you are adding a secondary video adapter to your system to run a second monitor and prefer not to replace your primary video card.

Windows 98, Me, 2000, and XP support this feature, and it can be very useful for some applications. To save a slot in your system, you can also use a dual-display card in your AGP slot. Replacing your single-display video card with a dual-display card is the best option today because most of the latest video cards in all performance ranges now support dual displays.

You also avoid driver, BIOS, and hardware conflicts that can result from trying to get two cards to coexist in the same system. If you are into gaming, you need one of the high-performance 3D video cards currently available. Modern games are very video-intensive, so be sure to check the Web sites, manuals, and even game boxes for the games you play to see which cards they recommend.

Although early 3D cards connected to the standard 2D graphics card, this design is now obsolete. High-performance 3D cards based on chipsets from NVIDIA and ATI provide both fast 2D graphics and excellent 3D performance. I recommend video cards with at least 1GB of memory if you don't play 3D games or are a casual gamer; 2GB or more is a necessity if you play a lot of 3D games.

Look for TV-out if you want to attach your system to a big-screen TV for presentations or watching DVD movies. If you want to add TV viewing and recording features to your system, consider a video card with video capture and editing features such as the All-in-Wonder series from ATI, tor NVIDIA-based systems featuring the Personal Cinema USB TV tuner.