In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear questioner, we would like to thank you for the great confidence you place in us, and we implore Allah Almighty to help us serve His cause and render our work for His Sake.
Muslims should have good names and give good names to their children. Islam does not require all converts to change their names. New Muslims should only change their first names, if they contain wrong or bad meanings. As far as their last names are concerned they should not be changed unless their parents are alive and accept the change.
In this regard, we’d like to cite for you the following fatwa issued by Dr. Muzammil H. Siddiqi, former President of the Islamic Society of North America:
Islam emphasizes that Muslims should have good names and give good names to their children. It is reported in a hadith that the Prophet (peace and blessings be upon him) said, "You will be called on the Day of Resurrection by your names and the names of your fathers, so have good names." (Reported by Abu Dawud)
During the time of the Prophet (peace and blessings be upon him) when people used to accept Islam, he would not require all people to change their names. He used to change only those names that carried wrong meanings or un-Islamic ideas and concepts. The Prophet's wife `A'ishah (may Allah be pleased with her) said about the Prophet, "He used to change bad names." (Reported by at-Tirmidhi)
For instance, `Umar had a daughter whose name was "`Asiyah" (meaning disobedient or rude). The Prophet (peace and blessings be upon him) changed her name to "Jamilah" (the Beautiful- see Sunan Abu Dawud, Hadith no. 4301) Abu Dawud has mentioned many names of people and places that the Prophet (peace and blessings be upon him) changed because they had bad meanings. (see Hadith no. 4305) Imam al-Bukhari mentioned that Sa`id ibn al-Musayyib said that when his grandfather came to the Prophet (peace and blessings be upon him), the Prophet asked him about his name. He said, "Hazn" (meaning Hard). The Prophet said, "You are Sahl. (meaning soft, easy)." The man said, "I do not want to change the name that my father gave me." His grandson Sa`id used to regret and say afterwards that they kept on experiencing the hardness in their family. (Reported by al-Bukhari)
One can only change one's own name, but one cannot change the family name or name of one's parents, unless they are alive and accept the change. So the new Muslims should change their first names, if they contain wrong or bad meanings. As far as their last names are concerned they should not be changed, because it is also forbidden in Islam to take the name of someone other than one's own biological father. Allah says in the Qur'an, "Proclaim their real parentage. That will be more equitable in the sight of Allah. And if you do not know their fathers, then they are your brothers in the faith…" (Al-Ahzab: 5)