I started using Ubuntu (12.04) a month or so back, I've not done much with it so I have only a few important files (particularly my Thunderbird profile). Yesterday I tried to upgrade to 14.04; the install seemed to go OK but after the restart my screen shows garbage (I suspect the video drivers were replaced by unsuitable ones). Because the screen is garbage I cannot access the system and hence not the files either. I need to get my Thunderbird profile back (I don't really care about anything else).
I tried to reinstall 12.04 but both the installation options wipe all my files. I abandoned that effort.
I have used the "Try Ubuntu" option from the live CD and (following a hint I found) I tried using gksu nautilus I could see the .thunderbird folder but my attempts to copy the profile failed with the message "Error copying file: Permission denied". I have tried changing the permissions on both the .thunderbird and destination folder (on a USB memory stick) with no success.
I would really like to get that profile back (I have a sentimental attachment to some of my emails!). Can anyone help?
It's probably obvious that I don't really know what I'm doing in Ubuntu so - please be gentle (in particular, I need detailed instructions if the use of the terminal is required)
Thanks in advance