In now older AWARD BIOS setups, there is the option labelled something like Update ESCD/DMI Pool which can be set to Disabled, Enabled, and on some boards, ESCD, DMI or Both instead of Enabled.
I have discovered that when this option is Enabled (or set to ESCD or DMI) that one needs to let the PC boot past this stage and start looking at drive booting. If this is not done, the option will not take effect. Furthermore, if you set to Enabled, exit and save settings, and then after the BIOS starts booting you then turn off the power or reset the computer before it has finished booting through the BIOS at least once, the option will still not take effect. This is because the option is only enabled for one boot only, and turning off or resetting the computer will set this option back to disabled. The system does not care about whether DMI/ESCD has already been updated - it will allow the option to be set back to disabled regardless of whether or not a full BIOS boot has taken effect since the option was enabled.
So the rule is to let the BIOS complete one full boot on it's own after enabling this option.