Ask an Electronics Question, Get an Answer ASAP!
Can you advise what the security code is for, for instance is it to access a online service to access your phone?
I haven't heard from you in some time, so can only provide generic advice at this time. Do come back to me should you need anything clarified.
Where its asking for a PIN code this may be the SIM pin so to reset that you need to request a PUK code which will allow you to reset the PIN. The process for doing this online is explained here