HP Vectra VL Won't Work With SWITCH BOX - Keyboard/Mouse Error!

[gplemos]

I just picked up two HP Vectra VL pII 233 machines to build a home network
for school. They currently have no operating system on them.

Their part numbers are: D5719N & D5051N

I have a manual switch box that allows me to use the same keyboard, mouse,
and monitor for up to 4 PC's.

On two other PC's I use this switch box on it works fine.

When I plug in a cable for the mouse and keyboard on either of the HP
machines (The cables are plugged into the switch box) I get a keyboard/mouse
not found type error.

(I happen to be using some conversion adapters to make the wires fit. Not
sure if this would cause a problem. Doesn't cause a problem on the two other
NON-HOP machines)

Is there something I should know about using these machines on a switch box
like I have? Something with the HP Keyboard and Mouse that came with the
PC's ?

The monitor works fine connected to the switch box on both HP machines, not
the mouse/keyboard.

The HP keyboard/mouse work fine when I plug them in directly to the HP
machines but not the switch box.

Is there a setting in the BIOS I need to change? Do I need to update the
BIOS? How do I know what version of the BIOS I have?

I heard there might be a keyboard voltage issue perhaps? Not sure about
this. Anyone who has had a similar problem with this and found a resolution
please contact me!

HELP!!