When windows 8.1 came out, we stayed on Windows 7. When Windows 10 came out, we stayed on Windows 7. We downgraded each new machine to Windows 7. Last year we gave a power user Windows 10 to find out how it operated with our collection of third party software. Two more were added over the year. A year later we are rolling out Windows 10 across the estate. I think this is the answer, we run a conservative strategy with regards to OS versions. We went from XP, to 7 and then to 10 and skipped all of the experimental versions. don't get me wrong, I tried them all, I installed Windows 10 on my laptop the day it was available, but not on my domain...no way.

We let WSUS install critical updates when it wants to. I don't install much else without a good reason. AV updates have caused a few freezes that have meant a couple of reboots are in order, but not much else.

I use Kubuntu and Ubuntu server and I have had some really annoying update issues with them too. I used to have an Apple laptop that after updates would disable it's own wifi and need a reboot.

> Have you ever had to deal with, say, per-CPU vs. per-user licensing for SQL Server?

No, but if I did it would be licensed once and then stay the same for years. I do have Oracle, like you mentioned before. That has a very quirky license, but that hasn't left me anything to do for 3 years since it moved server. It did 7 years on the old server!

I think one of the secrets of enterprise IT is conservative versioning, "n-1 is the version you want", I was told some years ago. A normal PC at our place would be running Windows 7, ERP client, browsers, and Office 2010. A number run Adobe cc and other things I can't avoid. We are looking at moving to Office 365, but if we instead re-buy Office 2016 we will stick with it for years. Perhaps that is the secret? It seems like you are unable to run this conservatively in your environment?