Easy guide to free Nokia unlocking:
(Please read the whole guide before starting)

1. Select phone model from list.
2. Enter IMEI number of your phone (Press *#06# on phone)
3. Select country and service provider where the phone was bought.
4. Hit the button: Calculate!

5. The software generate some Nokia unlock codes.
6. If 7 codes are displayed, use the code ending with +7 first.
7. If it does not work, then try +1, and finaly +5.
8. When phone displays "Sim restriction off" it is unlocked.
9. If only two codes are displayed (+1 and +2) enter both of them!

Codes will be shown on the form: #pw+CODE+n#
To get p, w or +, pres the * button several times.

You enter the codes correctly by removing any simcard from the phone, turning the phone on and then enter the code.

Important
You only have 5 tries to enter the correct unlocking code, if all 5 times fail you have to unlock it by cable.

Download:

It's nice way to unlock mobile using the unlocking code calculator..I unlocked my mobile using the code.
There is an site called unlock-free.com and also got the unlock instruction in the same site....