HP designed it this way so that if a corporate laptop is stolen, a thief cannot simply pull the coin cell battery to wipe the password. They must have advanced soldering and programming skills.
If you're prompted for a BIOS password reset code, you can try using the following code: How To Reset Bios Password Hp Elitebook 840 G3
Some users report HP has discontinued this service for older models like the 840 G3. 3. Generate a System Disabled Code HP designed it this way so that if