Apologies . You don't need a special BIOS. When a computer consistently produces a company name at the login screen, that name is not part of the Operating System (and cannot be removed with disk format). The name is embedded in the only other part of the operational part of the computer - typically this is the BIOS.
You should not have to deal with any of this, frankly.
I could be missing something, of course.
To me, it all sounds rather odd that your new computer is not "new".
I would guess the whole issue was unintended - a call to the merchant should help you resolve the problem.
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