From your decription of “prior to completing bootup process” and “not … user account” I assume this is the BIOS hardrive access password or potentially an SED (encrypted hard drive) password.
For the BIOS hardrive access password please check with the system or motherboard vendor for how to clear the password if that is possible. You cn see if the system has an administer level password set (which you know) that allows you to access or reset the password.
For encrypted hard drives, you will need to ask the person who set it unless someone set a recovery or second pasword on the encrypted drive.
On newer systems, the ability to recover from a forgotten password is much more difficult if not impossible unless you have also set an admistrative password.