Phone is locked no matter what sim card is in it

Did you use it with any SIM at all before this started happening? This message usually indicates that your iPhone is carrier locked and it cannot be used on other networks unless it is unlocked.

Alcatel may be locked into another network

go to the back of the Sim card and find for the puck code and then later dial and password is 1234 ok

the SIM code is the password/passcode for the sim card, no matter what phone you put it in, to keep your SIM safe from intrusion.

The Phone lock is the (usually) 4 digit pin to unlock the phone itself. this is more of a keylock, or an enhancement to the usual * unlock code.

if you don;t have a pin to unlock the phone, perhaps it is just * + green call button or something similar.

• PUK means "personal unlocking key" .
  The PUK code is asked if you enter a wrong pin 3 times.
  You need to call your phone service company, they can retrieve the puk code from a database
  for free.
  In your case you need to contact your SIM card phone provider technical support to unlock the SIM.
  The PIN and PUK are related to the SIM card, not to the phone.
  If you replace the SIM card with a different one, then the phone should not ask for the PUK anymore.
  Your rating is highly appreciated on this matter.

The phone is locked, but that doesn't matter, IT WILL NOT WORK WITH T-MOBILE!! Or AT&T or any GSM for that matter.

Yes, iDEN phones, the phones used for Nextel, do have a SIM card, but this is a very different SIM and will NOT work with any T-Mobile, AT&T, etc. SIM cards. Even if it were unlocked, that makes no difference. It uses a different technology. NO Sprint or Nextel phone will ever work on T-Mobile. Neither will a Verizon phone.

how do i unlock my samsung SGH-E900 to all networks??

thanks...

does not matter which carrier its with it can be unlocked anyway can do it for you

puk code doesn't matter with the phone ( d900)...
this code is on the sim card that you are using not on the phone

Chances are that virgin have locked your phone so that no other sim cards from other mobile networks can be used in it. You need to get your phone unlocked, which can be done either by virgin (which will be expensive, around £40) or you will probably find some store on your local high-street that will do it at a cheaper rate (normally around £10). When your phone is unlocked, you will be able to put any sim card in it, no matter what network it is. Hope this was useful!