Original post by: Philip Le Riche ,
This sounds like a UEFI password. After the 3rd attempt does it give a code? This is a recovery code and you can use it to get an unlock password from a couple of websites that Google (for some reason) doesn't index. There's a link to them in the External Links section at the bottom of https://therestartproject.org/wiki/UEFI_and_GPT If you're in legacy mode (it looks like old fashioned BIOS) then it may be possible to reset the password by shorting a couple of solder pads on the motherboard. On a set of Toshibas I unlocked last year they were visible under a bottom cover plate next to the RAM sockets, and it helped greatly to temporarily solder onto them a push button on the end of a long flying lead. Google may help you find them, if not try yandex.ru, which seems to have less scruples than Google.