To reset the password on a G6, you need:
HP has an internal tool called HP BCU Advanced and a hardware dongle called HP Recovery Key Dongle for authorized service partners. If you provide proof of purchase (original invoice), a service center will reset the BIOS password for a fee (typically $50–$100). They will not give you the utility; they do it in-house. hp elitebook 840 g6 bios password reset utility
The HP EliteBook 840 G6 uses a chipset-based (Phoenix/Insyde) BIOS lock. Unlike older models, there is no universal “backdoor” password. The password is stored in a serial EEPROM (often on the main BIOS chip).
Methods that do NOT work on this model: To reset the password on a G6, you
Older guides suggest using debug.exe in DOS or shorting the SCL/SDA lines on the I2C bus. These methods died with the Ivy Bridge architecture (circa 2012). On the EliteBook 840 G6, these attempts will result in a permanent brick requiring a motherboard replacement. Older guides suggest using debug
If you're unable to find a software-based solution, contacting HP support directly might be the best option. HP can provide guidance specific to your model and situation. They might require proof of ownership and could have additional steps or recommendations for resetting the BIOS password.
Previous generations (G4, G5) allowed for shorting pins on the SPI flash chip or using a simple DOS boot disk. The G6, however, utilizes a combination of the Intel PCH (Platform Controller Hub) and a dedicated EC (Embedded Controller) . The password hash is stored in one-time programmable memory within the PCH or a separate security IC (often an ST Microelectronics chip).