This might be a duplicate, but I didn't find any answer that fixes the problem. I have recently installed ubuntu 14.04 LTS and did not create a password for logging in. Now, if I try to use "sudo" command or if my screen is locked, I'm asked for a password. I tried the "System Settings" and "User Accounts" and I see a 5 digit password, which I have no idea what it is. Has anyone seen this before? This is not that I forgot the password, I simply did not set one up.