Username and password not matching in settings of mac book pro.

Hi i has recently changed my mac book pro's name from "apple" to "PruthviCodewave". Now when i try to change some settings a unlock prompt appears asking for "Username and Password". I remember my password through which i can login to my mac book and work daily but not able to change any settings. I tried both the username's but in its not working. Is there anyone who is facing similar problem ?