My colleagues over in enterprise product support often get corporate customers who report that “Your latest update broke our system.” After studying the problem (which is usually quite laborious because they have to go back and forth with the customer to capture logs and dumps and traces), they eventually conclude that, actually, the system was broken even before the upgrade! Their prediction is that if the customer takes an affected system and rolls back the update, it will still be broken. And if they take a system that hasn’t yet taken the update, and reboot it, it will also be broken in the same way.
And the prediction is true.
What is going on is that three weeks ago, the company’s IT department updated some software or installed a new driver or deployed some new group policy that they saw in a TikTok video or something, and the new policy does some really sketchy things like changing security on registry keys or reconfiguring services or changing some undocumented configuration settings. The software updates or the new driver or the new group policy renders the machine unbootable, but they don’t notice it because they don’t reboot until Patch Tuesday.
And then Patch Tuesday comes around, the update installs, and the system reboots, and now the new software or the new driver or the sketchy configuration settings kick in to make their lives miserable.
It wasn’t the update that broke their system. It was the fact that the system rebooted.
I've seen the full gamut of this.
1) The problem was caused by the update and the uninstalling the update fixed the problem.
2) The problem was caused by some prior update and the machine had a bunch of months of updates applied at once.
3) The problem was caused by rebooting.
4) The problem was unrelated to the update.
5) The problem was caused by the update and uninstalling the update didn't help.
For the last one: Windows 10 has full support for dynamic disks, Windows 11 does _not_. Upgrading Windows 10 to Windows 11 worked and failed to notice it...