To reset the BIOS password on an HP EliteBook 840 G3, you must use official software recovery methods or advanced hardware reprogramming, as simply removing the CMOS battery will not clear the password on this business-class model. 1. Use HP SpareKey (If Pre-Configured)
Because the password is saved directly on the BIOS chip, some users turn to hardware solutions: EliteBook 840 G3 BIOS Password - HP Support Community How To Reset Bios Password Hp Elitebook 840 G3
Once inside BIOS, navigate to Security and clear the administrator password. Method 3: Official HP SMC.bin File To reset the BIOS password on an HP
Are you able to produce the System Disabled code by entering the password incorrectly three times? EliteBook 840 G3 BIOS Password - HP Support Community Method 3: Official HP SMC
Some older HP EliteBooks (pre-G4) are vulnerable to a hardware short. This is not recommended for the faint of heart, but it has worked on some 840 G3 units with older BIOS versions (pre-2018).