A big bit OS, a little bit Hardware, so OS wins.

Where does the MacOS store its keyboard recognition 'code'?

Long story - a student borrowed my Chicony PC USB k/b to try it out. He dropped and broke it. I have a Genius brand PS2 k/b from my brief time on the Dark Side. I bought a PS2-USB adaptor, cheap as chips. I plugged the adaptor into the powered USB hub, whereupon the k/b recognition window opened. The MacOS obviously 'thought' it was a keyboard. In haste, and thanks to poor focus, I plugged the PS2 plug into the mouse socket on the adaptor. That upset the recognition process and MacOS indignantly told me it couldn't recognise the keyboard type, and gave me three options. I chose the US ASCII.

Typing is working fine, but some controls don't appear to be working terribly well. That may be the k/b itself. My thinking is to find where the MacOS has stored the information for this Genius k/b, remove that info, and start again with the recognition process. Can anyone enlighten me? Thank you.