There are "BIOS Crack" CDs (like older versions of Hiren’s BootCD) that contain debug scripts for very old Dell models (roughly pre-2012). These do not work on modern computers with UEFI and TPM security chips.
This will NOT work for new Dell models (2020 onwards) using BIOS version 2.0 or higher. Those use RSA encryption, which cannot be reverse-engineered by a simple online tool. dell bios password reset tool download
For older Dell laptops and desktops, the most common "tool" is actually a web-based . These tools use your Service Tag and the suffix to calculate a one-time backdoor password. There are "BIOS Crack" CDs (like older versions
Restore from backups and reinstall OS (if BIOS access not required) dell bios password reset tool download