Trouble with login !

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There can be a few different reasons for login to fail. Check the following:

• Passwords are case sensitive, so make sure Caps Lock is off.
• The keyboard mapping (such as US keyboard or GB keyboard) may have been one type during installation, but then another type when you are trying to login. Follow these instructions to change your password, which also gives you an opportunity to type some characters into the command-line and check that the keyboard is giving symbols you expect.
• There could be something mis-configured with your login manager. Try logging in on a virtual console (which you can switch to by pressing Control-Alt-F2 or Control-Alt-F3 and so on) to see if that works.