While searching for how I could get Windows to work with my Dvorak Keyboard (not hard-wired, just re-arranged keys) I came across this most unusual resolution to a problem in Windows 2000. (KB223056). It’s resolution was (when setup doesn’t recognise your Dvorak keyboard):

To work around this problem, press keys until you find the appropriate key that maps to the standard US-101 layout for that key.

Yeop, that’s what I want to be doing, pressing random keys when installing Windows.