If you are the owner of a GSM phone, then you should know by now that it can support different types of sim cards, which work on a various range of frequencies. Some time ago, mobile phones could only work on a certain frequency, but then appeared the dual band phones, and now, almost all cell phones have quad band support, so they can basically work with any carrier.

But when buying a phone along with a subscription or a pre paid card you will most certainly get a locked phone. Mobile carriers only sell locked phones when you buy from discounted offers, even if you dont decide to remain with that network for some time.

If you want to switch carriers or you youve simply bought the phone because it was a great deal and you planned the whole way to use it with your regular sim card, then you will have to unlock it.

Before you go ahead and enter just any unlocking code in your phone, know that any actions you take in this direction will void warranty rights. The idea of that warranty is to not unlock the phone for a period of time.

Still, you need it unlocked, and theres no point paying lots of money for this since there are plenty available programs, most of them free, and todays phones do not necessitate ( in most cases) additional hardware enhancements to work on other networks.

Downloading an unlocking software program on you PC is the best thing to do in such cases. You will need a way to connect the cell phone to the computer, by wire or Bluetooth. Once the computer identifies the connected mobile, you can go ahead and start the unlocker software. The phone model and number should appear on the screen.

If you have a Nokia, you should expect to see something like Nokia XXX written. Then, select the phone and you will see the frequency it has been locked in. The software detects restriction and attempts to modify base settings so that in the end the phone works on all available networks.

Be careful when doing this and is you have important files on your cell phone do a backup first, just in case. If you are unsure what to do, read the help file and ask for future assistance form program manufacturers. Press the unlock button only after you are absolutely sure your phone has been detected correctly and all files have backup versions.

After unlocking, try to see if the phone really does work in the desired network. Assuming you already have the sim card you were set to use in this phone, at this point you should get it and introduce it in the sim holder, then start the phone.

If it detects network setting and says nothing about the phone being locked, then its a good sign. Try and place a call or send a sms to someone nearby, so you can check the results fast.