How do I create a new user from the login screen??

view full story

http://www.ubuntux.org – Hello, I have a question. I've installed Ubuntu on my Windows PC, and am able to access both when I start my computer, My problem is that when I installed Ubuntu, it never gave me the ability to create a new user, So I Can't log in. How can I Create a new user from the login screen? Is there a user already there that I can access? if so, whats the user and password? I'm EXTREMELY new with Ubuntu. I've used it 3 times when I ran it as a program in Windows. Thank you!!! George (Distributions)