In the link below you can do the payment to buy the code for unlocking Bios or Hard-Drive password for your laptop Dell Inspiron 15 3521 (En el...
Dell Inspiron 15 3521 EC 2 MB Main 4 MB bios
Dell Inspiron 15 3521 (VAW00 LA-9104P Rev.1.0) (A00)
Dell Inspiron 15 3521 16 q bios
Dell Inspiron 15 3521 LA-9104P EC KB9012QF-A3 bios