We also used hard disk/floppy disk here in Europe (NL). My recollection is as the GP says, "disc" was only consistently used for optical discs (CD, DVD, BR). I

We also used hard disk/floppy disk here in Europe (NL). My recollection is as the GP says, "disc" was only consistently used for optical discs (CD, DVD, BR). It may still be that "disc" is European in origin -- the original CD came from Philips (NL) and Sony (JP) -- but for computer components, I've never seen it spelled "disc".