For safety reason, it is better for you to change WordPress default username 'admin' to something else.
This is an easy way to do it:
1. Log in to your WordPress blog as usual.
2. Go to 'Users' tab found under Dashboard on your left.
3. Click on 'Add New' which is located beside the word 'Users'.
4. Now you come to a page called Add New User. Fill in a NEW username, NEW e-mail address and NEW password (twice) in the boxes provided.
5. For 'Role', select 'Administrator'.
6. Now click 'Add New User' blue button.
7. Now you can see the newly created user below your default username called 'admin'.
8. Next, log out and then log back in using the NEWLY created Username and Password.
9. Go to 'Users' tab under the Dashboard and click on 'All Users'.
10. Move your cursor to the word 'admin', two words 'Edit' and 'Delete' will pop up. Click on the word 'Delete'.
11. Now you come to a new page called 'Delete Users'. Under 'What should be done with posts owned by this user?', select 'Attribute all posts to: (you can see your new user name next to it)
12. Click 'Confirm Deletion' button.
13. Now you should see only your newly created username and the username 'admin' is gone.
Now if you want you can change back to your original email address.
14. Click 'Your Profile' and look for 'E-mail (required)', and change back to your original email address.
15. Now your blog post is shown written by 'your new username'. If you want to change back to your nickname or your actual name, you need to type in the name which you want it to be publicly display in the box next to 'Nickname (required)'.
16. Then as for the 'Display name publicly as', you select the nickname which you want it to be seen on your blog post.
17. Click 'Update profile' blue button below.
