Windows Won't Detect New Device

My PC has four USB ports, and they're all full. Rather than using a USB hub, which I've heard can be problematic, I bought a PCI card that gave me another six USB ports and a pair of FireWire ports to boot. When I installed it, however, Windows appeared to detect it but couldn't properly identify it or accept the installation of the included drivers.

There are essentially two reasons why Windows doesn't detect a device, or detects that a device has been added but can't identify it properly: either the device isn't compatible with Windows XP, or some other device is causing a conflict.

You can test the first hypothesis pretty easily by consulting the documentation or checking the manufacturer's web site for XP compatibility.

The second possibility is a little harder to troubleshoot. You'll encounter this problem mostly in desktop PCs as opposed to laptops that have a bunch of internal expansion slots. (Laptops have fewer expansion options, and thus fewer opportunities for conflict.) The system BIOS and chipset are responsible for parceling out IRQs to all the devices in your system, but when you add a handful of cards to the dozen or so devices already built onto your PC's motherboard, devices must share IRQs, and that's when the conflicts start making life difficult.

You can confirm that this is the problem by simply moving the card to a different PCI slot. This fools Windows into thinking the card is an entirely new device, which gives you another shot at installing the right drivers; the new location may also eliminate a conflict with a device on your motherboard. Despite Windows's plug-and-play capabilities, you may have to shuffle PCI cards in a full system until you find a setup that works.

If you still aren't having any luck, enter your PC's BIOS setup screen, find the "Reset Config Data" option (sometimes called "Reset NVRAM"), and set it to Yes. When you're done, save your settings and reboot. This setting makes the BIOS reset and reconfigure all your plug-and-play devices every time your system starts, which forces Windows to do the same. The change may increase boot time, but you can turn it off later, and it may be just the thing to get all your devices to work in harmony.