After Avast manual update Windows 10 "can't sign into my account"!

[jure.aurin]

After manually updating Avast program to 20.7.2425 yesterday, I can't log into my Windows 10 account. ("Preparing Windows..." and after a while:"We can't sign in to your account.") I get a temp account. Tried system restore several times, Safe mode, multiple restarts, disabling Avast shields... Nothing. The same message every time.
Coincidentally, yesterday I also installed Avast Free Antivirus Offline Installation (same program as on my PC) on a several years old HP laptop (also Windows 10 Pro). Installed OK, Smart Scan OK, but on restart starts showing "Preparing Windows" and never starts. Now it is still unusable.

Any thoughts would be really appreciated.

[strakl]

Just a question, why do you blame avast right away, yes, you updated it, yes it might be but try to examine it a bit more, for example, what apps did you install recently, drivers, etc etc. The possibilities are endless, avast is just one of those.