If the laptop is worth less than $100 (e.g., old Dell Latitude E5420), it is more cost-effective to recycle it and buy a used replacement.
Search for "Dell BIOS master password generator (old version)" or "Phoenix BIOS password decoder." Input your Service Tag and, if asked, the "8FC8" hash. dell 8fc8 bios master password
On Dell desktop computers, removing the CMOS battery (CR2032) for 10 minutes and draining flea power (holding power button) will reset the BIOS password. On , this rarely works because passwords are stored in non-volatile EEPROM memory. If the laptop is worth less than $100 (e