I am going to expand on @dinoo_fixit's answer as they missed key details. When you get the master password, it's case sensitive. On the D series and early E series machines you enter it and press Shift+Enter, then it gets you past. However, you need to go into the security menu, put the master password in the administrator password box and leave the other boxes blank - this will clear it out. Once you do that, save the changes and exit the BIOS.