Currently Being ModeratedMay 6, 2012 7:07 AM (in response to faisal90)
where did you bought this phone? your phone is locked to some carrier. you must contact that carrier to unlock your phone . no one can do it otherwise and dont post your imei no anywhere in the internet
Currently Being ModeratedMay 6, 2012 7:37 AM (in response to faisal90)
Contact the carrier it is locked to. Assuming it is locked to AT&T, and you are/were actually an AT&T customer who either fulfilled your contract or paid the early termination fee (or purchase a no commitment phone), then you can have it unlocked.
If you are/were not an AT&T customer, they will not unlock it. The phone is useless to you. Sell it and buy one in the UK.
If it is a Verizon or Sprint phone, just sell it. You can't use it at all. Those are CDMA phones and will not work on a GSM network.