New
#111
There were problems with the April update and computers using Avast reported (failure to boot).
Avast issues a fix for the Windows 10 April 2018 Update problem - MSPoweruser
Windows 10 April 2018 Update problems: Users struggle with mystery 'black screen' | ZDNet
Avast publishes a guide; How to fix the boot lock in Windows 10 April 2018
Avast Shares Fix for Broken Windows 10 April 2018 Update Machines
Avast blames Microsoft for Win10 1803 upgrade blue screens, nonsensical options | Computerworld
Once the computer is bootable and there are backups (files and image) you will have more freedom to troubleshoot.