This web page describes multiple ways of deleting the admin password.

You need to call Dell support if you've set a password you don't remember.

Upon verification of ownership, they will assist in unlocking the system.

I meant the admin password in BIOS setup, not a Windows password. Windows is not even installed on this machine.

Thanks ejn63, I remember the password very well since I only set it recently. I was in fact able to remedy the situation and delete the offending admin password in the meantime, but it wasn't trivial. Other users are sure to have a problem with this. Let me explain:

Since the "Enter the old password" box is greyed out, it will not react to any clicks and you therefore cannot enter anything into it. What you need to do is click on an available (active) field within the setup page and tabulate your way to the "Enter the old password" field. Note that none of the greyed out fields will be highlighted, so you'll need to count your way to the "Enter the old password" box. In my case I clicked on the "Enter the new password" field in the System Password section and tabulated three times backwards (shift+tab). Once you're there you press enter, a new window opens up asking you to enter the current admin password so you can make changes to the password field. Then the "Enter the old password" box becomes active, you click on it to highlight it and enter the old admin password again. You can then enter a blank password in the "Enter the new password field" and confirm it to clear the admin password as usual.

I consider this a Priority A bug and would urge the kind support team at Dell to fix it if they wish to save their users time and effort.

Cheers.

Ok, on closer inspection it turns out there's an "unlock" option in the Admin Password box in the upper left which accomplishes the same thing I described earlier. The GUI on this BIOS is quite different than Dell's arrangement on previous BIOS generations so I did not notice this option until now. Never mind.

This BIOS usability is terrible. Once you typed the old password and pressed enter, it does not focus the "Enter new password" input box. Just click in the box where you should type it, type an empty password (press enter twice) and save.

@luizdeluc​ Thank you for this. I couldn't find this info anywhere.