My in-law's laptop "upgraded to Win 10 all by itself" last week (that's how they described it), and I can only suppose that one of them closed the nagging pop

My in-law's laptop "upgraded to Win 10 all by itself" last week (that's how they described it), and I can only suppose that one of them closed the nagging pop up, unknowingly triggering the update. After rebooting, neither the keyboard nor the trackpad would work. I had a spare USB keyboard (no mouse), and I managed to delete the faulty drivers, which were replaced on reboot by valid ones (the bad drivers were reported as 'up to date', so updating wouldn't do it). Disabling all the spyware features with only a keyboard during the post-install setup wasn't fun. Thankfully, the device manager is still his old Win95 self, and I could easily navigate through it even though I haven't owned a Windows machine since XP. I learned after the fact that refusing the User Agreement would revert to the previous version of the OS. I wish I had known that before finalizing the impromptu upgrade.