Also, if the floppy is not bootable, the system will halt, waiting for user intervention. This is a very good point. You can also save wear and tear on your floppy drive by not accessing it unnecessarily on every reboot. To change the boot sequence, you must change the CMOS configuration settings. Most systems prompt you to press a key, such as Delete or F1, during startup to run the setup program that lets you change the sequence.
Configurations differ, but the boot disk sequence is typically part of the advanced settings.
Note that many systems will also let you boot from a CD-ROM drive.