The HP EliteBook 840 G6 is a highly secure business machine, and standard "easy" tricks like pulling the CMOS battery rarely work on this generation because the password is saved directly on a non-volatile BIOS chip
If you find a website claiming to have an "HP EliteBook 840 G6 BIOS Password Reset Utility" for download: hp elitebook 840 g6 bios password reset utility work
These are scams. They either ask for a "license key" (which you pay for and never receive) or they install remote access trojans (RATs). The HP EliteBook 840 G6 is a highly
“The Great BIOS Lock Escape – Not Magic, But Clever” Verify presence of drive encryption and collect recovery