Q&A
Q You stated that there are only 16 IRQs (interrupts) available for use by devices installed in a PC. As I examine the information on IRQs in SysChk, however, it looks as though most of the IRQs are being used by the PC on devices that I did not install; there are not many IRQs left for me to use for additional devices. Is it possible or likely that I may run out of IRQs?
A It is not only possible, it has become a serious problem for a lot of users purchasing new PCs.
You're right when you noticed that most of the IRQs are being used by devices you did not install and that when you start adding devices, IRQs can appear to be in short supply. Many users are now discovering that by adding a SCSI card, a sound card, an internal modem, a network card, and so on, that they are running out of IRQs. There are ways to juggle IRQs—you can turn off devices not being used and you can sometimes enable two devices to share an IRQ, provided they are not used simultaneously. In later chapters, I'll give you some tips on how to make the best use of your scarce IRQ resources.
Q If most versions of Windows ship with utilities that can detect my PC's configuration, does that mean if I am running one of these operating systems that I do not need a utility such as SysChk?
A After you gain some experience in diagnosing and troubleshooting problems in your PC and become more familiar with hardware configuration issues, you can probably abandon (or at least put away on the shelf) a utility such as SysChk if you are running one of the most recent versions of Windows. When you are just starting out, however, I suggest that you use every systems analysis resource available. You may have noticed that the utilities in Windows aren't quite as thorough as SysChk or that the information is not presented in such a neat, easy-to-use package.