Credits to @hereugo for sharing us an effortless method to reset Nokia security code of the QWERTY/full keyboard devices like Nokia N97 and Nokia E72.
Quote of hereugo:
no neeed this software to reset security code especially nokia e72 and n97 just follow this instruction and you done
The way to button-press Hard Reset your E72 isthe SAME as the N97. Hold these buttons:- Capslock- Space- Backspace and Press the power on. As usual, keep thebuttons pressed and your phone reset as 12345
All you need to do is holding Capslock + Space + Backspace and press the Power button. Your phone's security code will reset to the default code 12345.
For Nokia non-QWERTY devices
If your Nokia is non-QWERTY device, there are other ways to reset or search back your Nokia security code:
How To Reset Nokia Security Code
Find Back Your Nokia Phone Security Code