Q: won't let me reset password in recovery mode/terminal. So I can get to my desktop to work.

I am running 10.9.2 Mavericks and had not had a problem till now. The computer is brand new and the only update I did was from 10.9.1 to 10.9.2 the day it came out. Now I Can't login to startup my computer. Booted in recovery mode and used terminal to resetpassword. That didn't work so I am unable to get past login to show my desktop. please help I had tried every key command to boot in various options and nothing works.