Avast antivirus program is blamed by some users for crashes and blue screens during the last major update Windows 10 Απριλίου 2018 Update.
A relative and in-depth description of the problem posted on reddit and reports In short, most systems that have the same unpleasant symptoms when upgrading to Windows 10 April 2018 Update had the Avast antivirus program installed.
This might be the proof that possibly a recent update of Avast could have compatibility with Windows 10 April 2018 Update, causing errors in the operating system, which the users can only be resolved by reinstalling Windows completely.
Systems running Avast antivirus show three boot options after upgrading them to Windows 10 April 2018 Update. Windows Rollback and Windows 10 on Volume are displayed twice. While the first option triggers a reboot, the other two try to complete the boot to end up with a blank, black desktop without icons and a loading error message on the desktop.
Reddit user gcdrm says he works on a small store computer repair, and reveals that many systems upgraded on May 20 and 21 experienced the same problems.
"So far, the only solution we've found is to reinstall Windows," they said. “It seems that everyone who has fallen victim to this problem has used Avast Antivirus. However, this problem only occurred on systems that attempted the 1803 upgrade in the last two days. This implies that a very recent Avast update is blocking it procedure upgrade. The read/write permissions appear to be corrupted.”
While neither Microsoft nor Avast recognized the issue, Reddit users recommend users who are offered the Windows 10 Upgrade 2018 Update to uninstall Avast antivirus before starting the process. No action is required for users who have successfully completed the upgrade.
For you I do not think Avast is to blame because I have total bitdefender and I did uninstall and reinstall now if both are to blame I do not know