Before you open the chassis, attempt the easiest method: generating a master password. Dell has a known flaw in older BIOS versions where you can enter a special "Service Tag" derived password.
This method is successful for clearing settings , but may not always clear a password on newer firmware revisions. It is worth trying as the first hardware step.
This 32-character code is printed on the physical drive label.
: Type the generated code into the password field on your Latitude 7480. Critical Step : Instead of just pressing Enter, you key and then press to apply the master password. Method 2: Clearing the CMOS (Hardware Reset)
Whatever the case, a locked BIOS (Basic Input/Output System) turns your laptop into an expensive paperweight. You cannot change boot order, disable secure boot, reinstall the operating system, or even sell the device.
If successful, the laptop may beep or display a "CMOS Checksum Error" and boot straight into the BIOS, asking you to set the date and time (indicating the settings were cleared).
Once you have successfully reset the password, avoid this nightmare again:
: Press Esc , then select Yes to save changes and restart. Method 2: Use a Password Release Code (Forgotten Password)