Hi. If you have forgotten your screen lock (pattern, PIN or password) then see http://www.satechhelp.co.za/1184/Reset-Sony-Xperia-St27i-Screen-Pattern-Pin-Lock - Otherwise, do kindly repost advising the carrier you are with if this is a Network Lock related question. As for a SIM PIN, you will need to contact your carrier/service provider's customer support for your PUK.
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