From EVDO-Forums by J.C. Roberts
"The CMOS settings which you set, such as the current date/time, are not the only thing that is remembered between power cycles. Your box also remembers the mapping/remapping of resources to most of the installed hardware and adapters. In some CMOS user interfaces, it's called "Plug-n-Play Settings" but it's also called "ESCD Settings" and "NVRAM Settings" and probably others but even worse, there are some systems from Dell, IBM and similar which do not give you a simple way in the user interface to reset/clear the ECSD (Extended System Configuration Data). This is stupidity at it's finest, and resulted in the "Old Solution" outlined above. On most Dell boxes and probably others, you can actually reset/clear the ECSD settings but you have to know the super secret dance steps required.
1.) Enter the system CMOS settings ("System Setup") by hitting the F2 key when booting up (i.e. at the Dell logo screen).
2.) Hit the Num Lock key until the keyboard numlock light comes on
3.) Hit the Scroll lock key until the keyboard scroll lock light comes on.
4.) Hit the Caps Lock key until the keyboard caps lock light comes on
5.) Press Alt+E and many of the boxes made in the last 5 years will beep to let you know the ECSD data has been cleared.
There are probably similar dance steps for other systems from other vendors that lack a straight forward way to clear the ECSD settings, so you'll have to go digging through their sites/docs to figure it out.
On the first boot up after clearing the ESCD, the BIOS will rebuild the info by probing all the installed hardware. This should solve the ignored/missing hardware problem that some people face but if clearing the ESCD settings fails (or you can't find out how to do it), then try the "old solution" of removing all your adapter cards, booting the system, shut down the system, install one card, boot the system, shut down the system, install the next card ...