Hello
i found some cain of solution, is in here i made the post. so i copy and paste....
I just step whit this windows10 and avast issue I can reinstall the system without losing applications or docs or conf
This windows10 dont want to install the spring update or do anything, just load the ER after read everywere, it look like a problem with avast
How i manage to solve this, i'll try to explain.
In the ER (environment recover) I manage to load the windows10 with the black desktop, is some cain of safe mode without the save mode-... weird, load some things. I connect the network cable just in case.
Go to troubleshooting and them try to load another operating system, the option. In my case i have 3 options, rollback, and 2 option with windows volume 3, i choose the third, and try several times to load the black desktop be patience take sometime to load.
When load, execute tasks manager, control+shit+esc, and execute any browser, internet explorer those the tricks and search avast uninstall. download the app, execute with win+r and uninstall.
After that i execute from a USB the installer of the spring update ISO and install the win10 and preserve all data and applications.
It takes almost several hours,4 h. to restore the win10 but i recover all.
Hope it helps
Sorry for my English is my third language
cu