That was interesting!
With SLP 3.0, OEM SLP keys are no longer used at all. Instead, a tool is used by the OEM to embed a unique key each computer's BIOS, making consumer versions of Windows 8 and later very difficult to pirate.
Yes, that seems to tally with what I thought (especially about the BIOS ) but I didn't know about the XP era. I'd sold my company by then - up to then, selling CAD workstations was like having a machine that printed money. 9k for a big plotter, 2,600 for a 21" monitor, and a grand
extra for an Imprimis Wren 150mb drive upgrade.
And there was me telling people not to get windows - having loads of toys taking up valuable memory space would never catch on.
A bit of history about the early era: The Cambridge Computer Graphics double slot card sold at 9 grand. I took one to Texas to show manufacturers there to see if they could make them under licence. When they ran it on test the room fell quiet - they knew it was in a different league. When the boss was called, he wasn't surprised. He's started his company after visiting the UK and seeing an earlier card at a show in Brighton.
Shortly after, it was all over. AutoDesk rewrote AutoCAD in such a way that it could not make use of the ASIC chip which had been the big investment.