Need to change the login screen

[applebutter]

I just purchased a very nice imac 27 late 2013 from ebay.

The computer came installed with Yosemite, when the computer boots it comes to the login screen, the background is gray with an 8 ball icon above where I place my password.

Is there anyway to change the screen to anything else?

 

[fisherking]

System Preferences>Users & Groups, should be there...under Current User..

 

[applebutter]

Thank you that worked!