Unlock code for Dell 3360

You need to call Dell support with verification of ownership.

@ejn63​

yes, I contacted them , they need a service code to solve it, but it was erased from the bottom of the laptop

@Majixx​ 1) Windows + R

2) enter cmd 3) type wmic bios list full

you will find it in the serial number section. 

if the machine really belongs to you or you have the invoice to prove the ownership ( new or refurbished ) wear and tear, fading out is quite common once the system gets old. dull printing, environment etc etc.

bios serial number is burned by the manufacturer in the, motherboard tpm chip.  

if it helps like , and mark as accepted answer.