Is there any OS that allows this config?

At least with Linux, if I encrypt my hard drive, I have to enter my encryption password on every login, for some even during boot.

Not sure about Windows. I wpuldn’t be surprised if you can have bitdefender on with auto login.

At least with Linux, if I encrypt my hard drive, I have to enter my encryption password on every login, for some even during boot.

Look up TPM.