Hello, here is my problem. I have googled this and tried several versions all with no sucess. My laptop had crashed when updating from 11.10 to 12.04 so I had a fresh copy of 12/4 made and installed it onto my laptop as a CLEAN install. I forgot my password about 2 nights ago and changed thru the method explained by booting grub then recovery option followed by root shell prompt and password change no problem. Yesterday when trying to update my password had some how changed. I then followed the same way as done before but now recieve a authentication error password not changed. I am solo user as this is my pc and is only used by me. No settings were changed and recieved or was told of any time term when password needs to be changed as read in forums. Bear with me im no techie not by a long shot. when ive attempted to access /etc/shadow got permission denied. My pc is a gateway NV53A52u/15.6lcd/500gb hdd ubuntu as only os. 4gb ram. Also have now noticed the lp now boots to grub menu where as before went straight to the ubuntu front page. Any help is greatly appreciated. Just remembered i changed one thing that was no password required for login. Would reintalling and starting all over be my only option at this point?

Just a guess but maybe a live cd and than
mount the hard drive
enter the local environment (as root of course)
drop down to runlevel 1 (like this: "init 1")
and try to do the "passwd"

Maybe? IDK
It should be possible if you never encypted the hard drive