After Build 17035 installed and rebooted, there was the message Windows ran into a problem and had to reboot. And another one, collecting information. Then, the same thing happened, 10 times until finally, I succeeded to restore Build 2025. That took 9 hours.
This morning I tried to resolve the problem. I got to a tech by the name of Adrienne C, who told me that she is familiar with the problem and will restore and repair files which are probably damaged. I also told her that I have a problem with my HP OfficeJet Pro 8610 that the HP people could not fix because it was the Build's problem.
After about an hour that she took control of the system and downloaded the full Windows. I was cut off from her.
I tried to get help again. I got to a person by the name Zeus who promised me that he would help, to tell me after 20 minutes that this is an Insider's issue and he cannot do anything about it.