Onsight Data

 Before trying anything else, contact your service provider and ask for an unlock code. Usually, if you've been a customer of theirs for some time, they will provide you with an unlock code for free. This is, by far, the best way to get your phone unlocked.

1. Download software to generate the unlocking code. Software is available on some websites for free and some pay websites that also offer support if things go wrong. See external links below.
2. Find the Serial number of the cell phone, also known as your IMEI number. This can be done by either removing the back of your cell phone and looking underneath the battery, or simply by typing in *#06# into your cell phone. It should be something like: 010082321439976/07951780736
3. Using the software you have downloaded, enter in your Manufacturer (which is in this case Nokia), and sliding the card out. Put the battery back in and power the phone on.
4. You will see a message "Insert SIM Card". Enter all of the characters you see in your code, including the # symbols. To get a 'p' press * 3 times, to get a '+' press the * key 2 times, to get a 'w' press the * key 4 times. Disregard any spaces in the code.
5. In order to unlock your phone you generally need to enter only one code. Start with the first one. If your phone is not unlocked by typing the first code (MCC+MNC), use code "7" (Multilock)
6. Once you have finished entering a code that works you should see a message that says "SIM is not restricted" or "Restriction off" message depending on your model. If not, try entering another code. Message "Cannot undo restrictions" means the phone is "hard-locked" and cannot be unlocked by code.

[edit] Tips

• Unlocking only applies to GSM phones. Phones using other cellular technologies cannot be unlocked without special software and hardware.
• Switch off the phone. Hold the keys "3", "*" and "Call" and switch the phone on. Keep the buttons held down till you see the word "Formatting..." on the screen. Make sure that the battery is full charged before you attempt this. This should reset the phone lock code.
• If you want to avoid the hassle and sometimes "waste of time" in trying to persuade your cell phone provider to give you an Unlock code or trying to use free software that is out dated and only works on old cellphones,
• You can purchase an unlock code from a trusted source www.FreeYourCellphone.com
• They can unlock your cellphone to work with any other GSM network world wide for a small fee and Guarantee there results with a 100% money back policy.

http://www.wikihow.com/Unlock-Your-Nokia-Cell-Phone