Booting without a Keyboard
When setting up a server or any other sort of headless machine, booting without an attached keyboard can be somewhat problematic. However, most new off-the-shelf consumer computer hardware has an included BIOS option that explicitly allows you to boot without keyboard. I have found this to be the case on almost all systems capable of using a USB keyboard. Older systems may lack this feature, but nevertheless the issue is also addressable from the BIOS. These older machines [should] have a bios option regarding error halts during POST; to boot successfully without a keyboard, one is simply required to select that errors "halt boot on all but keyboard." (thats the phrase most often used, or some variation of it). Failing that - for even older and/or non-standard equipment, a very simple hardware level workaround is available.
During boot, most [most*] systems detect that a keyboard is present and active by monitoring the current levels in the keyboard port. In order to circumvent this check, merely wire a 10K ohm resistor between ground (pin 3) and +5 volts (pin 4) on any standard PS/2 style keyboard connector. If the keyboard is an older PC/AT keyboard - the large 5 pin connector version - you may simply use the same wiring scheme with an AT-to-PS/2 adapter. Alternatively, connect the resistor between ground (pin 4) and +5V (pin 5).
With truly ancient parallel port (DB25) and serial port (DB9) keyboards, the above approach may also help you to find success. Your mileage may (will) vary.I highly suggest using an extension cable from the motherboard port so that you may detach this setup. Otherwise, inserting a resistor directly into the motherboard port will work too. Note that the pinout of each connector is somewhat counterintuitive:
(perspective of looking into the connector on the keyboard, not the PC. The character "n" denotes the notch in the shield around the connector.)
* by most, I imply "not all." Some systems insist upon initializing the keyboard circuit, setting the caps/num lock, etc. Therefore, this keyboard loopback trick with a resistor will not work on every system; as with everything, your mileage may vary. However, in general, if it does NOT work, one of the other methods usually will.