Introduction

Hardware provides a foundation for software BIOS, operating systems, and applications programs to do its work. Earlier PC operating systems CP/M, DOS, and Windows 1.x-3.x interacted with but rarely intervened between software and hardware. Programs could reach out and touch discrete CPU, memory, disk drive, and COM-port bits at will. Ever since OS/2 and Windows NT, through Windows 95, 98, Me, 2000, and XP, operating systems have become significantly more involved in both isolating hardware from applications to provide for better security, reduce device conflicts and embracing hardware to create a richer user experience.

The first 20 years of PC hardware saw constant contention over architecture limitations, connections, I/O port standards, and driver conflicts that led to many errors, lockups, and nonfunctional systems. In recent years PC hardware has evolved away from pushy and proprietary hardware implementations to better standards supporting more cooperation and interoperability with fewer conflicts, not to mention universal technologies that also work in and with Apple and Unix products. There are still many exclusive PC-only products in use by many users, but eventually we will have only hardware based on ubiquitous standards that make products more economical and interchangeable with other systems.

Legacy devices had obscure and often complex configuration requirements. Today's Plug and Play products let you seamlessly move from a PC to a Mac as often as you like without the base computers and operating systems freaking out. Also, while it may now be unusual to find a modem that uses an old serial COM port, or a printer that uses the old parallel LPT-port, an add-in card that uses an 8-bit ISA-slot, or software that comes on 5.25" diskettes, they still exist and are supported by most PCs and their operating systems alongside newer technologies.

Plug and Play is Microsoft and the PC industry's first effort at trying to eliminate the technical barriers of switches, jumpers, and obscure configuration details that befuddle users and technicians, and keep consumers from tackling the marvels of PCs. It is supposed to provide for the automatic detection and nonconflicting configuration of hundreds of types of hardware devices, from keyboards to network cards, FLASH memory chips, and digital cameras. These are excellent benefits, but they only succeed when all the devices and the system BIOS work properly together.

Plug and Play support began as early as Windows 95 Supplemental Release 1, and it has improved with each subsequent version of Windows. Plug and Play itself has not changed substantially, but has definitely benefited over time from more cooperation among hardware vendors and driver software programmers. While much progress has been made in bringing along Plug and Play with PCI, USB, IEEE-1394/FireWire©, AGP, PCI-X, ATA, and S-ATA, they all have new and different configuration and operational issues when we get to current hardware and Windows XP. Windows XP itself does not have a lot to do with Plug and Play except to listen to what the BIOS tells Windows about the system and attached devices, but Windows can vividly reveal the symptoms associated with poor Plug and Play performance and general hardware misbehavior that you need to know about and be able to resolve.

PC administrators constantly add, troubleshoot, upgrade, and reconfigure hardware, from system boards to myriad USB devices, and have to deal with system BIOS updates, changing BIOS and I/O device parameters, and digging in to Windows' Device Manager. In this chapter you will explore and learn about many different aspects of hardware and drivers related to Windows XP, what you need to know about devices and configuring them, as well as interactions among other devices and software.