I am working on a customers laptop, and got rid off the problems it came in with (seizing to a stop as soon as he logged on). As a favour, I let the outstanding updates install. First of all the updates stuck at 99% updating for an age. But eventually it went into the restating phase, and stuck there forever. After a few restarts, it decided that the updates had failed, and started backing them out. This took a long time, and eventually it got in the restarting phase, and stuck there forever again.
This turned into an endless loop, each restart went through the same process.
In the end, I forced it into the automatic repair function, by powering down as soon as the windows logo appears – twice is the magic number.
Automatic repair of course failed (has it ever worked for anyone?), but I then went into the troubleshooting options, and restarted in safe mode. After a brief foray into completing the updates, windows 10 started in safe mode successfully. This gives me the option of documenting what apps and programs are loaded so that if a rebuild or reset is finally required, I at least can get somewhere close to what was there before.
Restart again from safe mode into normal mode, and it starts fine, but the original problems are back! Just 3 days taken so far! At least I have a machine that starts again!
The seizing issue may be connected with the updates issue, I will work on that assumption for a while.