There are several reasons why the installation or finalization of one or more Windows updates can hang.
Most often, these types of problems are due to a software conflict or a preexisting issue that simply wasn't brought to light until the Windows updates started installing.
I had some issues with installation that I suspect might be tied to shutting down the PC while the updates were downloading.
By the way, with Windows 10, this is the installation of a whole new operating system and not just big update like Windows 8.1.
Don’t start your upgrade unless you have time to let it finish and don’t need your computer right then.
If you don't see anything at all on screen, especially if you think the updates may have been installed completely, see my How to Fix Problems Caused by Windows Updates tutorial instead.Most of the time, Windows Update does its job with little if any attention from us.While we might check and install updates manually from time to time, most Windows 10 computers are configured to apply important updates automatically while older versions, like Windows 7 & 8, usually apply these fixes the night of Patch Tuesday. In any case usually when the laptop shuts off while in the middle of an update it screws up the operating system.You are going to have to re-install the old OS from the laptop's recovery partition. Sometimes however, when the patch, or maybe even service pack, is being installed during shutdown or startup, the update installation gets stuck - freezes, locks up, stops, hangs, clocks... Windows Update is taking forever and it's time to fix the problem.The installation of one or more Windows updates is probably stuck or frozen if you see one of the following messages persist for a long time: is all you'll see on screen.A sudden power cut means the computer won’t be able to shut down cleanly.You may lose work and the file system might be corrupted.If you ever used Windows 95 on an old computer, you’ll probably remember how you had to turn off the PC.You opened the Start menu, clicked Shut Down, and waited patiently for the computer to finish up whatever it was doing.