Recently found an Apple iMac 20" A1224 (2009) on the side of the road and want to wipe and reinstall (don't know former user password).
I'm using a regular wireless keyboard (is this the problem?) and Command+R does not respond. I have tried a few other options no luck!
I have no idea what os is running but, I assume it's probably El captain. Please help I want to turn this into a retro arcade for my son.