Registry key for Disabling Avast’s Windows PE boottime scanner

Under the key

For Avast: HKEY_LOCAL_MACHINE\SOFTWARE\Avast Software\Avast\properties\settings\BootTimeScan

For AVG:

HKEY_LOCAL_MACHINE\SOFTWARE\AVG\Antivirus\properties\settings\BootTimeScan

Create string value and set name to AllowWinRE

with a value of 0