How to get the PC's setup menu (or BIOS menu) to show up.

PCs have a secret life. Beneath the surface, every PC has a small, mostly hidden operating system that gets the computer going before the "other" operating system takes over.

This unheralded mini operating system is the BIOS, the "Basic Input-Output System." The name is well chosen. It's "basic" because it does only what's needed to get the computer to run properly. It deals with "input" (things attached to the computer that give it clues about what's going on outside, such as a modem or a keyboard) and with "output" (items such as printers).

Unfortunately, there's no such thing as a "standard" BIOS. Windows and Linux PCs are all descended from the original IBM Personal Computer of 1981 and the improved IBM Advanced Technology (AT) computer of the mid-1980s, so in many ways they are a lot like their grandparents. But PC manufacturers are free to make changes to the BIOS and to other features of their PCs -- IBM doesn't control any aspect of PC design -- and each year you're likely to find a new function added and an old one taken out.

Such is progress. But this comes at a cost for all of us who have PCs. Just trying to figure out how to change a basic setting on your computer can take hours away from your weekend.

The BIOS setup menu, sometimes simply called the BIOS setup, is the only place you can make many of the important configuration changes to a PC. It controls whether your PC can boot from another disk (such as a CD-ROM or a floppy) if the hard drive is acting up, for example. It also lets you turn off basic features you don't need, such as the old-style printer connection (called the parallel port) on computers that have a USB printer.

You've probably seen a notice on your PC's screen about the BIOS setup many times. When your computer is getting itself going, the BIOS usually places a brief message on the screen telling you how to activate the BIOS setup menu to show up. The message might say something like this: "Press F2 for setup." (F2 is just used as an example.)

The idea is simple, but the execution sometimes can be frustrating. You have to press the key before the BIOS finishes starting up the PC. I usually get my timing right, but sometimes I have to keep hitting the right key a few dozen times before the BIOS notices all my efforts.

The key you're actually supposed to press might be a simple one such as F2 in my example above or a strange concoction such as Ctrl-Alt-Enter. Watch the screen carefully when your PC starts up to see if the keystroke or key combination is shown. If it's not, look in the guide that came with the computer. (Many manufacturers never bother to tell their customers this information, but you might have more luck.)

If you can't find anything that tells you which key (or keys) to press, look at the list of BIOS keystrokes accompanying this article. It's an old list and might not help much, but you could try all the keystrokes to see if one of the combinations works.

You could also do as I've done many times when trying to fix an "mystery meat" PC: I reboot and then press as many different keys as I can, noting carefully which ones I've just pressed so that I'll know which ones worked. (I know, it sounds dumb and it probably is. But desperate people do desperate things.)

Once you get the BIOS setup menu to appear, do yourself a big favor and look at the instructions. They're always right on the screen, and they always refer to keystrokes that move you from one part of the configuration menu to the next. Take careful note of how to back out of the menu when you realize that you probably shouldn't mess with it if you don't really know what you're doing.
(Your mouse won't work in the BIOS menu, so you have to get around by pressing keys.) (Not true it works on some Emachines and some other brands that I don't remember.)

The only safe thing you should change at this point is the boot order. You'll find a submenu that lists the order of "devices" or drives that your PC will boot from. If it does not have the CD-ROM listed first, change it so that the first choice is the CD-ROM and the second is the hard drive. That way, you can insert a Windows or Linux installation CD (or any bootable CD) into the CD-ROM drive and reboot to get the CD to run its installation program.

BIOS setup keystrokes
The first item is the key or key combination. The second is the model of PC or the maker of the BIOS. You'll see some companies listed many times, with different keystrokes. That's normal. (It's not that manufacturers can't make up their minds. It's just that they change suppliers and use different BIOS setups.)
Delete: AMI or Award BIOS.
Esc: Toshiba
F1: Toshiba; Phoenix; some IBM PS/1 models.
F10: Compaq.
F2: NEC.
Insert: IBM PS/2.
Tab: eMachines.
Reset button (press twice): Some old Dells.
Ctrl-Alt-+: Various computers.
Ctrl-Alt-?: Some old IBM PS/2 models.
Ctrl-Alt-Enter: Some Dells, others.
Ctrl-Alt-Esc: AST, Tandon, others.
Ctrl-Alt-Ins: Zenith PCs, Phoenix BIOS.
Ctrl-Alt-S: Phoenix BIOS.
Ctrl-Alt-Shift with Del (on number pad): Olivetti.
Ctrl-Esc: Many PCs.
Ctrl-Ins: Some IBM PS/2s.
Ctrl-S: Phoenix BIOS.
Ctrl-Shift-Esc: Tandon