Updating Windows 10 To 11, Get 0x80004005 - 0x1000A Error

Trying to update Windows10 to Windows11 using MS Installation Assistant.

Before updating I turned all of the Avast Core Shields off (File,Behavior,Web,Mail), also turned off Avast Firewall, only then started updating.

This went fine until the end of the installation when it stopped and returned the error “0x80004005 - 0x1000A
The installation failed in the DOWNLEVEL phase with an error during PREPARE_FIRST_BOOT operation”.

Googled for what this meant and these said I have to 1st try stopping all 3rd party anti-virus programs (Avast).

I thought I had already done this by stopping the Avast Core Shields? Does this completely shut down all Avast blocking of the system so I can successfully update? Or do I have to completely uninstall Avast to update? Maybe there is one button I can press to shut Avast down completely, then update? Please advise - thx.