I'll share an anecdote with my story from Microsoft.
Way back in 2007 I bought a Microsoft bluetooth keyboard and mouse to replace my Logitech that kept dropping connection and "sticky key"ing (connection drop, last key hit was repeated until I could reconnect). For some reason, the driver install would complete, but it wouldn't actually pick up the keyboard and mouse. Then I read it needed Windows installer 3.0 (I think?), but I had 2.something. Uninstall/reinstall a few times, nothing. So I call tech support and get an Indian listreader. Nice enough guy, but stuck to his script, and I uninstall/reinstall/reboot a few times. Then he asked a couple pointed questions and said he'd arrange to have an OS guy talk to me 'tomorrow', so we set up a time.
Tomorrow hit, I did get a call from the same guy, and he patched in one of the MS OS guys. The OS guy sounded like he was from the West coast. He runs me through a couple things, gets me to boot into restore mode and gives me this arcane command line to try to force remove or update of the Windows installer. No such luck. He then tells me "you know what I'm about to tell you, don't you?" "Yup, reinstall and patch up the OS" "Do you have a backup?" "All my files are on another partition" "I do that to!!". Turns out you need Windows installer to add, remove, or update windows installer. And if windows installer goes tango uniform, you're S.O.L. and J.W.F.
So yea, at least in this story they start with the lowest common denominator, but they were able to get the right level soon enough.