Otherwise, if the computer finds a boot record on the hard disk ("C:"), it will boot from it, and it won't even try to boot from the floppy drive ("A:").
It may also be desirable to boot from the CD-ROM drive, for example if you want to try out Linux without actually installing it.
In order for this to be possible, the computer must check the CD-ROM drive before the hard disk.
Before attempting to change the boot sequence, it is very important to understand the following things: 1.
The program that can change the boot sequence is usually called something like "CMOS Setup Utility" or "BIOS Setup Utility".
This Setup utility program has nothing to do with any program called "Setup" (or any other program) in your proprietary operating system. If you are making this change in order to try out Linux from a bootable CD-ROM, it is important to keep in mind that this change also has nothing to do with Linux.
This article will concentrate on configuring "PCs" or "IBM-compatible" computers to boot off the CD-ROM drive.
If you are using another hardware platform, you may skip to the end of this article, where other platforms are discussed.
When a computer boots, it looks for a "boot record" to load into memory.
The possible places where the computer can look for this boot record are the hard disk (called the "C: drive" on so-called "PCs" or "IBM-compatible" computers), the diskette drive (the "A: drive"), and the CD-ROM drive.
(Some computers also allow booting off a location on a network.) The computer can be configured to look for this boot record in any one of these three places, or to look first in one place and then in a second place, or to check all three places.
The computer will boot from the first boot record it finds, so not only is it important where the computer looks for a boot record, but also the order in which it checks these places (called the "boot sequence" or "boot order"). Most of the time, most users want to boot their computer from the hard disk.