I have a machine that had Windows 7 and had been upgraded to Windows 10 3-4 months back and have had no problems with it.
Last Friday, I installed some internal company software and restarted. During the restart, I could tell that some Windows updates were installing. Once the machine finished the installs, it rebooted and then went to a blue screen with an error 0xC000021A. After trying all available troubleshooting steps (nothing worked, including safe mode), I reset the machine and kept my local files.
The machine restarted successfully. I installed Office and Visual Studio, checked for and let it download all updates (there were many), restarted and left for the weekend. When I came in today, it was back at a blue screen.
I reset it once again and then checked for updates without installing anything else and restarted. Blue screen again.
Reset it one more time, but this time, checked for updates, then downloaded the troubleshooter from here, https://support.microsoft.com/en-us/kb/3073930, and then hid all updates it allowed me to hide (which seemed to mostly be hardware updates). And then restarted (because some updates, specifically KB3133431 and KB3124266, couldn't be hidden).
And it blue screened, yet again.
Unfortunately, I can't find any one else who has had these issues. I don't think it's hardware related because the Office and Visual Studio installs worked just fine and the system runs fine until the Windows Update install completion kicks off during restart.
Why, oh why, can we not pick and choose which updates we want to install anymore? I'm sick of getting BSODs simply from running one of your updates.