I can authenticate but can not login in using my password?

Question

Here is my story :

• there were days when I had my password and everything was fine.
• I removed my password :
  • Opened User accounts
  • Unlocked it by pressing "Unlock" button
  • Selected my username (btw, I have only one user which is Administrator user)
  • Chose "Login without password"
  • Pressed "Change" button
• and some day there came a trouble
• i needed to authenticate (as I had no password I could not authenticate)
• using Startup Disk Creator wrote Ubuntu 12.04 to a USB.
• I "tried Ubuntu"
• mounted my Ubuntu's filesystem (not Try Ubuntu's)
• in terminal run gksu nautilus (No authentication was necessary)
• opened etc/shadow file, and removed some_encrypted_text from this line :
  • wicked6:some_encrypted_text:15864:0:99999:7:::
• Rebooted and opened my Ubuntu
  • in terminal run passwd myusername and changed my password
• I got the message passwd: password updated successfully
• I can use this password for authentication but not for logging in by pressing login button (I can log in directly on first log in {Remember that I had used login without password}. But when I lock my screen I need to press switch user and then press login, because when I enter my password it does not accept it)

Please don't advice me to reinstall Ubuntu, because I don't want. Help me to login in on Lock Screen. Thanks in advance.

P.S. I am using Ubuntu 12.04 :-)

Answer 1

If you chosen "Login without password" this is useful only to pass by the login screen without password. This doesn't mean that you don't still have a password. You will still need your password sometimes (for example when you use a command with sudo or gksu).

I can advise you to change again your password to the old one from terminal with passwd command and search for /etc/shadow~ (with~ at the end) file or /etc/shadow- (with- at the end) file (this is a backup for /etc/shadow file). If you find it, rename it with the original one (sudo mv /etc/shadow~ /etc/shadow).