If you have a Dell computer, either a laptop or a desktop, the password can be calculated but you need to find your service tag. This service tag is usually displayed on the screen of the locked out Dell computer.
Dell BIOS Service Tags
The BIOS service tags for Dell computers have the pattern of 7 characters with a 4-character suffix. Example of service tag for a Dell BIOS:
Where can I locate such code? Simply enter a wrong password in the BIOS login prompt, make three (3) failed login attempts and you shall see the lock code and the service tag of your Dell computer.
Dell Hard Disk Drive (HDD) Service Tags
The service tags for Dell HDD have the pattern of 11 characters with a 4-character suffix. In older or newer Dell system, the codes are padded from the left with asterisks ** or *** then followed by 9 or 8 characters and a 4-character suffix. Examples:
NOTE: The following Service Tags are NOT supported: -1D3B, -1F5A, -1F66, -3A5B