|I am assuming that, when you say "will not start its black screen," you mean that you are needing the BIOS password not the OS password. |
Open case, locate and remove the CMOS battery. Wait 15 minutes or so. Removing the CMOS battery clears the CMOS of all stored data, including the password.
After you replace the battery, boot and then enter the BIOS setup where you will have to reset it to your desired configuration (or load default values).