Is it necessary to change one's name upon converting to Islam, and have any hadiths been narrated in this regard?

It is not obligatory to change one's name after embracing Islam, unless the name involves servitude to other than Allah, such as 'Abd al-Masih (servant of the Messiah)' and the like. In such a case, it must be changed due to its contradiction with Islamic doctrine. However, if the name is ugly, such as 'Harb (war)', or contains self-praise, like 'al-Zahid (the ascetic)', it is desirable to change it, but not obligatory. Islam encourages good names and forbids self-praise. The Prophet, peace and blessings be upon him, changed the name 'Barrah' to 'Zaynab'.