Troubleshooting

Can't Select the Primary Display

I can't get my multimonitor system to choose the primary display properly.

As discussed in the section about multimonitor arrangements earlier in the chapter, it can be tricky to force Windows XP to use a particular video display card as the secondary display. If a display card isn't disabled from running in VGA mode, the computer runs the card's Power-On Self Test (POST). When that happens, Windows XP assigns it primary display status; if the other card's VGA mode can't be disabled, you will not be able to use the secondary card. Most users will want to keep their first video card as the primary display, so they need to know how to prevent the POST from happening.

Generally, dual-display works best when one video card is AGP and one is PCI. However, this doesn't guarantee that the faster AGP video card will wind up being your primary display. You may need to set the system BIOS option for default video to PCI to enable an AGP+PCI dual display to work properly.

If your video card has a jumper block or switch that can be used to disable VGA mode, this option will make it easier to use the card as a secondary card, since only the primary card needs VGA mode. VGA mode is used for the system's power-on self-test (POST) and to display startup options before the Windows GUI is initialized.

Many desktop systems with onboard video automatically disable the on-board video when you install a PCI or AGP video card, making it necessary to install two video cards (or a multi-monitor video card) if you want multiple monitor support.

Generally, you can't tell if a secondary card will work until after you boot Windows XP with the secondary card in place, the system detects it and installs the drivers, and the system tries to initialize the card. If the card is initialized successfully, you should see the Windows desktop on both screens. If the secondary monitor's screen stays black, check the Device Manager listing for the video card. If the card is listed with a yellow exclamation mark, it's not working properly. A Code 10 error on the card's properties sheet's General tab indicates the card was unable to start. Restart the system and change the default display setting in the BIOS and retry it. If necessary, try a different slot for the card.

Altered BIOS Settings Prevent Computer from Booting

I've altered my BIOS settings, and now the computer won't start.

Today's computer BIOSes have so many arcane settings that it's quite possible to alter one that will prevent proper booting. Before you futz with the advanced CMOS settings (not just the simple stuff like time, date, boot order, power settings, ports, and such), read the manual that came with the computer or motherboard. If you decide to change something, write down the old value before doing so. When in doubt, don't alter advanced CMOS settings that affect how the chip set works, whether and where the BIOS and video shadowing is done, and so on. The default settings are designed by the motherboard maker to work under most situations and operating systems. Because Windows is the most popular operating system, you can bet it was already tested and configured for Windows 9x, NT, 2000 or XP (unless you have a very old motherboard).

That said, what do you do if you've changed something in the CMOS and now the computer won't boot? You can try the computer's or motherboard's manual or Web site for information about settings for Windows XP. If you find nothing, then you should wind back the settings to the factory defaults.

TIP

Most CMOS setups have a "Set to Default" or similar command you can issue. This should get you out of most any jam.

The Set to Default option might also be a good course to take if you make CMOS settings that prevent your computer from booting and you can't remember how to undo the changes. The Default settings are usually conservative enough to work under most circumstances. The BIOS in some systems may also have a "Fail-Safe Defaults" option that sets your BIOS to its most conservative settings.

If what you've done has changed the hard disk "Type," or if you manually entered the number of sectors, tracks, platters, and so on, and now it won't boot, use the Auto Detect Hard Disk BIOS setting to discover and enter those numbers automatically (this is known as drive autotyping).

New Hardware Doesn't Work

I've added some hardware, but it doesn't work.

Try these steps, in this order:

1.	Try the troubleshooters included in the Help system, assuming the hardware fits into one of the neatly packaged categories. Open them through the Help and Support page as described previously.
2.	Try rebooting Windows XP.
3.	Use the Computer Management Console and the Device Manager to check resources assigned to the hardware to be sure that it's not conflicting. Check the hardware's manual to determine whether you should be setting some DIP switches or jumpers on it to avoid conflicts if the device isn't a Plug-and-Play device.
4.	Open the Device Manager, locate the device's entry, and hit the Delete key to delete the entry. Then, power down, remove the device, and restart Windows.
5.	Power down again, add the hardware back again (running the Add Hardware applet if the hardware isn't detected at bootup), and configure as necessary.
6.	Check Google; search to see if anyone else has written about the problem and its solution.
7.	Check the manufacturer's Web site. If it has a "Knowledge Base" feature, search that.
8.	If you purchased the hardware from a local store, contact them for assistance.
9.	Contact the manufacturer via email or phone.