For these models, only HP’s official SMC.bin (via support) or hardware reprogramming works.
She tried removing the CMOS battery, but that didn't work—the password is stored on a separate chip, not the battery-backed memory. The Solution: Using HPBR Hp.probook.elitebook.bios.password.reset.utility.hpbr
Hp.probook.elitebook.bios.password.reset.utility.hpbr: A Complete Guide to Unlocking HP Laptops For these models, only HP’s official SMC
This utility is not an official HP product and should only be used by technical professionals. Improper use can lead to corruption of system BIOS data. What is the HPBR Utility? Improper use can lead to corruption of system BIOS data
Incorrect use of master password generators can put the BIOS into a permanent “Security Violation” state, requiring soldering of a BIOS chip.
HP's official method for unlocking a BIOS is to provide a unique SMC.bin file. While you may find this by searching on forums, the only safe way is to contact HP Business Support directly. You will need to prove ownership of your laptop, and HP will then send you the customized SMC.bin file along with instructions on how to use it to reset the password. This is the most reliable method, as it does not risk damaging your device and is often provided free of charge.