warning: you will need to reinstall all programs if you reinstall windows!

warning: if you connect your hdd to other computer not with usb cable, but directly, i am afraid you may boot from it and infect the healthy hdd, so you sould carefully choose boot device. also you should be afraid of running programs from the infected hdd manually or by some autostart mechanism, though as far as i know that autostart was in windows xp, but it is not very actual with more new versions of windows, since it is disabled by default.

warning: you may lose your windows’ activation! i think my windows key was saved in efi partition, you may need to find and write your windows product key to a paper.

for that (reinstalling windows), i have connected its hdd via external case with usb cable to a linux, and deleted windows and program files (except some configuraion files of programs in appdata), (also i deleted users directory and others, moving my files to another folder before that), (just deleting whole c: partition, moving your files to other place before that, may be faster, if you have files of little total size), and deleted some partitions, except EFI boot partition, though that was dangerous, i hoped it (the EFI partition) was not infected. then, i created new windows 10 iso and dvd and reinstalled windows using it.

about not deleting efi partition: i thought my windows key was saved in it. i think i could get windows product key using some command or program from inside the old infected windows, i am not sure whether i could get windows key from that partition by other method. i think i could, if i had windows key, alternatively change gpt partition scheme to mbr and delete it (the EFI). i had seen that windows did not install due to GPT if i put laptop to non-EFI mode. or, if i was sure i can get windows key from the efi later, i could remove boot flag from it instead of deleting it.

alternatively, instead of reinstalling windows, you can try to check your windows hdd with other antivirus, installing it to same system, or, better, to other machine, and connecting this infected hdd to it, and booting from the healthy hdd.

why i did not just run windows installer from inside the old infected windows installation? because it was recommended to me to format all hdd and to boot from the installer dvd in order to not infect fresh installation. i believe in this principle, and, as i said, i just delete some files instead of deleting/formatting all partitions, because formatting would require a new hdd to move files to it.

alternatively, you can try to get old state of your system from some backup system… (there are also windows’ built-in system or systems, and you may have one from laptop manufacturer and you may have made backups manually or get them automatically). (this may delete your latest changes to your files, so you may need to save such files somewhere).

alternatively, you can reinstall windows from laptop manufacturers’ special partition. i have not used this way, because windows 8 was there, and i wanted to try to install a “vanilla” windows, ie without the additional preinstalled soft.

I can’t tell what is causing it…my guess is the windows update, currupted files or applications.

Any suggestions?

This is in your article. I must say that Windows Defender seems to “Enable” itself frequently, after a Windows 10 Update. I have had to “Disable” Windows Defender because it does not “play nicely” with Bitdefender Total Security 2018 and Bitdefender does not always “Disable” Windows Defender. I have been getting strange notices, since this last attempt to Update. I have to go into Security and fix Windows Defender, twice now. This has to be part of the reason for the Failed Update times 4.

Just saying this has been my experience for the past week or so. This also very easily could be unique unto me, only. }:O)