The reason for this question is typically somebody is trying to use a SIM card other than that provided by the network operator who provided the phone. Network operators sell their mobile phones at a much reduced rate in order to entice customers into a contract of typically 12 or 18 months. In practice what the operator is doing is adding the cost of the cell phone into the monthly contract charge for the service. This is why they put in place restriction codes to ensure that the mobile phone cannot be used with another carrier while they recoup its initial cost.
The Samsung Galaxy Tab is the long awaited tablet release from gadget manufacturers Samsung. Named Galaxy after their popular range of Android smartphones, the tablet will be an enhanced tablet version of the Galaxy smartphones, with all the same features and more. It boasts high definition touch screen display, perfect for enjoying games, movies, apps and the web in the palm of your hand.
You can get a new SIM card on any network for next to nothing from most phone retailers, supermarkets and the internet. To get the unlock code for a HTC Sensation XE, the best thing to do is first ask the people who had it locked in the first place, your network service provider. If you have been a long standing customer of theirs the likelihood is they will offer it to you for free, and may even offer to do the unlock for you in one of their high street stores.