The BIOS (Basic Input/Output System) is used to find the device on which the operating system is located and starts it up. It's also used for the initial hardware configuration and hardware low-level access.
The appearance of plug'n'play devices and their widespread use means that all modern BIOSes can initialize these devices. In order for Linux to recognize plug'n'play devices, your BIOS must be configured to initialize them.
Changing your BIOS' settings is usually performed by holding down the Del key (some BIOSes use the F1, F2, F10 or Esc keys instead) right after the computer is switched on. Unfortunately, there are many types of BIOSes. Therefore you will have to look for the appropriate option yourself. It's often called (or ). Set this option to No and the BIOS will then initialize any plug'n'play devices, which helps Linux to recognize them.
All recent systems can boot from a CD-ROM. Look for Boot sequence or First boot device in the BIOS' features setup, and set the CD-ROM as the first one. If your system can't boot from a CD-ROM you will need to use a floppy boot disk.