Proof that leaving things to the last minute is just bad IT practice and stupid!
So Windows 10 has been available for free for a year. Plenty of time to run trials, dual boot systems, check it out and so on. Plenty of time to be a responsible IT person. Plenty of time to find out that Windows 10 is the best MS OS ever, and it was free, for a year. Guess what, many device drivers from Windows Vista work cleanly on devices that weren't supported on Windows 7.
I'm just an amateur home user unlike 'Reg Man" here, except that I have had only one failure, the ATI graphics chip on a ten year old Toshiba laptop that was way overdue to be put out to pasture anyway.
What I didn't do was leave it to the last minute and then blame Microsoft for my own incompetence. Ten year old peripherals, yeah, they are working, supported or not. Sometimes with Windows 7 64 drivers, sometime Windows Vista 64 drivers. No need for a new BIOS for my old Intel Mobo. PALM PDA, remember those, over 10 years old, syncing quite happily with an open source driver!
Most of these problems can be addressed with a little planning and research. That's what good techies and professional IT people do. They don't upgrade their critical business systems 24 hours before the deadline and expect everything to work.
So, @TheDanold - Don't blame Microsoft for your lack of planning and irresponsible attitude. With a little forethought most of these things can be fixed, but lack of planning is your own problem.
So, given your sample size of four systems, if you give yourself time, you can probably complete the upgrades to Windows 10 successfully in the future, it just won't be for free. Let's see, three failed systems, so that's between around $350 and $600 for new W10 license upgrades. What is a little planning and forethought worth?
Above all, you have left things to the last minute, and then tried to pass the blame to somebody else. Frankly, I do not find that a very credible stance for someone trying to be an IT professional.