Removing a BIOS password from an HP EliteBook 840 G1 is significantly more difficult than on standard consumer laptops because security credentials for this business-class model are stored in non-volatile memory (EEPROM) that doesn't clear just by removing power Method 1: HP SpareKey (Self-Service)
If you set up recovery questions when the laptop was first configured, you can reset the password directly: how to remove bios password hp elitebook 840 g1