How do I lock or unlock a memory card on my Nokia phone 6650 and 6790 Surge?

To set a password to help prevent unauthorized use, in the File manager view, select the memory card and Options > Memory card password > Set. You are asked to enter and confirm your password. The password can be up to eight characters long.

If you insert another password-protected memory card into your phone, you are prompted to enter the password of the card. To unlock the card, select Options > Unlock memory card.