Well, today, on a Toshiba satellite, Microsoft warned me with it would install Windows 10 in 3 minutes right as I signed on (replacing 8.1), and I wasn’t able to stop it.
It restarted the machine. The entire process took about 85 minutes. It seemed to wait a long time at 92% and 69% on the driver installs.
Still, there is a problem with Microsoft doing this. What if I had to catch a flight and depend on the computer for a business trip that day?
Update: May 19
The New York Times purports to answer my questions in New York Times Tech Fix, "Why Windows 10 Upgrades Go Wrong, and How to Avoid It" (p. B6, Business Day, May 19). Cheaper laptops may not have upwardly compatible device drivers.