immigration

Hello:
There is one important piece of information missing from your question, which is the country of origin for the child and whether that country is a member of the Hague Convention on International Adoption. The following consequences flow from that difference:

1) If child's country of origin is NOT a member of the Hague Adoption Convention (e,g, the U.S. has become a member since December 2007), the OLD rules and procedures still apply. The basic requirements are that: a) the adoption gets finalized before the child turns 16 years old, b) the U.S. citizen adoptive parent had 2 years of legal custody/residence with the child before the I-130 petition is filed.
Under the OLD rules/procedures, the child can still file an I-485 application for adjustment to residency within in the U.S. even if the child is "out of status" as long as the child entered legally and can show proof of legal entry. Under that scenario, it is not necessary to go through NVC processing and turn in the DS230 as that means that the child will be applying for an immigrant visa through OVERSEAS consular processing.
It sounds odd that your friend managed to get an adoption decree from a foreign country while the child is residing with him in the U.S.. You might want to double-check that the adoption is valid and your friend did not provide any misstatements (e.g. that he resided in the foreign country with the child for a specified period) in order to get the foreign adoption decree, as either the Dept. of State or the USCIS may halt or deny the visa processing at a later stage on that basis.

2) If the child's country of origin is a MEMBER of the Hague Adoption Convention and the adoption was finalized after April 2008, then NEW rules and procedures apply. Under this scenario, your friend can no longer file an I-130 petition, but file an I-800 or I-800A petition. Under the new procedures, the child's country of origin (called the SENDING country) will have designated "Central Authority" that will conduct an investigation into whether the adoption meets the requirements of the Hague Convention (e.g. whether it is in the child's best interests, whether there was some monetary inducement paid for the child to be adopted, etc.). Different countries will have their own methods of complying with the Hague Convention.

You can visit my website for more information and a link to the Hague Convention on this subject.