Actualy your wrong, The BIOS is a separate Chip then the CMOS, the CMOS contains settings then can be changed through the CMOS setup, such as time, boot configuration and overclocking settings, so when people say, change it in your BIOS, they are wrong, they mean CMOS, The BIOS IS NOT stored on the CMOS, the BIOS does not require continues voltage to retain its settings, since the information on the BIOS is physcially burned into the Chip. However The CMOS does require continuious voltage to retain its settings, this is why there is a small Lithium coin cell battery near it, so when the computer is off, the battery provides the volttage.
The only time the BIOS can be changed is if its EPROM or EEPROM, and you would have to flash it.
If you would like to argue more, read an A+ book or look it up online, I am 100% sure I am correct.