Two monitors on one computer . . . Is that possible?

Question: I’m trying to get two monitors to work at the same time on my computer. It uses Windows 98 Second Edition. I am using an AGP video card and I’m trying to install a 64-bit PCI video card as the second video card. The problem is when the PCI card is in a slot, it becomes the primary card and the computer doesn’t seem to find the other AGP card. When I reboot the PCI card, it works fine but I can only use the one monitor. Do I need to upgrade my BIOS or change some other setting? — Bill

Answer: Some video cards simply don’t support this feature. You don’t mention which brand of card you are using, which is important. Here’s what you need to know:

Windows 98 Second Edition allows a user to attach two monitors and two video cards in a single computer — to allow more space to work with. For example, you can launch a word processing program on one monitor and an e-mail program on the other and move your mouse cursor between the two.

The problem with most new and exciting features is that there are a few glitches in the technology.

One, two, or more video cards can indeed be used with two or more monitors in one computer, but only if the drivers they come with support the feature.

What does that mean? A driver is the software that allows a computer to “talk” to a device. In fact, a driver is a translator. It understands what the computer wants to do and speaks to the device to tell it what to do in its own language.

Drivers are usually provided by the manufacturer of the device and have to be installed when the device is installed. The drivers of some common devices are also included on the operating system’s installation disk.

Two kinds of video cards support the multiple display features: AGP (short for Accelerated Graphics Port) cards and PCI (short of Peripheral Component Interconnect) bus cards. The difference between the two is which connector is used to attach the card to the computer’s motherboard.

AGP is a faster technology since it allows the video card to directly access the computer’s main memory — this helps with 3D graphics rendering. Toss that kind of lingo about AGP technology around a computer video game player, and they will think you’re pretty smart.

When you use two video cards on one machine, they don’t have to be identical, and one can be AGP and one PCI, but not all cards work with Windows 98 SE.

For example, the Permedia chipset on cards from 3Dlabs won’t work with 98SE (although their Permedia NT and Permedia-2 chipsets do, according to Microsoft’s website).

The RIVA 128 Video Adapter also won’t work with the multi-display feature.
“When you add a secondary video adapter to a computer that uses a RIVA 128 video adapter as the primary video adapter, the computer may stop responding (hang),” says a bulletin on the Microsoft Support Knowledge Base.

The cards that do support this feature are listed on the Microsoft website at http://support.microsoft.com/support/kb/articles/Q182/7/08.ASP.


To enable the multi-display feature on a Windows 98 SE machine, follow these steps:

  1. While the computer is turned off, add any additional display adapters (video cards) and monitors.
  2. Start the computer and boot up Windows. Install the display adapter and monitor drivers (if necessary), and then restart your computer if you are prompted to do so.
  3. Click the Start button, select Settings, and then click Control Panel.
  4. Double-click the Display applet, and then click the Settings tab.
  5. In the Display box, click the adapter you want to use, and then click the Extend my Windows desktop onto this monitor checkbox to select it.
  6. Click OK.

There are a few quirks with this technology. According to Windows 98 Second Edition, the Unauthorized Guide (Que), by Paul McFedries, there are five you should keep in mind.

Quirk #1: One of the video card/monitor combinations is designated as the primary card, and, as such you can only run DOS full screen on that screen.

Quirk #2: When you run DOS in full screen on the primary screen, you can’t use your mouse on the secondary monitor.

Quirk #3: Some programs display dialog boxes and shortcut menus on the primary monitor, even though the program is running on the secondary monitor. Some prorams hate dual monitor set-ups.

Quirk #4: If you try to drag the program’s window onto the secondary monitor the program will hang. Graphics programs particularly resist.

Quirk #5: If you move a program window to the secondary monitor. That program will likely open in the secondary monitor the next time you start it.

(For those wanting to do this on Windows NT…look at this article: http://www.tcs.org/ioport/jul98/dualmon.htm)