DELL blocked by BIOS password

all of these solutions I know them and I even tried them. My DELL is a laptop. And, according to this document, the only technique to reset the BIOS on a laptop is to remove the CMOS battery for a few minutes (which I did).

In general BIOS passwords are stored in a CMOS-type memory; sometimes removing the battery is enough and sometimes you also have to short it or use this software:
http://www.tadpu.com/systeme/configuration-et-outils-divers/telecharger_pc-cmos-cleaner-supprimer-le-mot-de-passe-bios/

But there are also passwords stored in an EPROM memory and well, good luck with that because apart from reprogramming the EPROM I don't really see how to do it.
After that indeed you can send it back to Dell and pay an arm and a leg for them to reset it.

Update :
I went to Dell's site; they explain how to do it, except that this procedure is for a desktop motherboard; you have to see if there is something similar for laptops. Here is the link:
http://support.dell.com/support/edocs/systems/opgx260/en/sm/sysbrd.htm
Sharing is the basis of knowledge. In information technology in theory practice is the same as theory, but not in practice... so be curious!

Hello,

This one is normal; it is not stored in volatile memory, so removing the battery will not change anything. It’s an anti-theft system.

You need to go see DELL; they have a utility that allows you to unlock it, but first you’ll need to prove that you are the rightful owner ;-)

Look it up on Google with the message it gives you; there’s a lot of information about it.
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Hu?

Sorry, I thought your PC was a desktop. I don't have the solution right now but I will look on my side to see if I can find something that could help you.
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Sharing is the basis of knowledge. In computing, theory and practice are the same in theory, but not in practice... so be curious!

Hello

The answer was given by aiglenoirdu29

On portable devices, the password is not stored in the main CMOSS for security reasons in case of theft.
You must go through a professional to unlock it, with the PC purchase receipt proving you are the owner.

Anyway:
https://www.commentcamarche.net/infos/25871-pourquoi-commentcamarche-n-aide-pas-a-trouver-un-mot-de-passe/

No one can certify your good faith.

Hello to you.