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I am a new Ubuntu user with 12.04 lts and stepped away from my computer for a month and forgot my password.
Using this forum I attempted to reset my password using a root line upon booting in grub, I followed instructions to find I was getting results that no one else had gotten. asking for reset options that I didn't understand how to use, it said the the argument was invalid, So I found a way to delete my encrypted password in a nano list. I was able to log in but Sudo still seems to recognize a Password and even thought my user account profile says "none" after password I can't seem to do anything.
I don't know what else to do, hopefully it can be fixed. the long explanation was to show my inexperience and give light to any mistakes made.