I've had this problem in modern times where, when setting up Windows PCs (via WinPE at our enterprise) some NICs would very occasionally not work right with the

I've had this problem in modern times where, when setting up Windows PCs (via WinPE at our enterprise) some NICs would very occasionally not work right with the provided driver and end up with some default MAC. Doesn't work out so well when you have a room full of these PCs all getting imaged at thhe same time and suddenly half a dozen on the same switch have the same MAC. :\ (I believe it came down to a BIOS problem and a new version sorted it out.)