I am using Ubuntu 12.04 LTS on a USB on an HP Pavillion.
I posted a problem about removing Thunderbird. I was advised to use GKSU Nautilus to become root, or as I understand it, SUPERUSER. I could NEVER get it to work and I am now afraid I have screwed up my whole LINUX system. I can't get stuff to mount and then other stuff says it can't unmount (see images)
I have read that either using sudu or gksu can possiblibly lock the user out entirely. It seems that I am completely locked out as an administrator I can't even access the system settings/user accounts!
I am now completely overwelmed. I even tried to create a new USB loaded with 12.10 and was willing to overwrite everything and start new, but without being able to mount another USB I can't even do that.
I was going to (in desparation) try and run 13.04 from a DVD. I got as far as getting the ISO and it's files onto a DVD but now the DVD won't mount so I can't use it.
Have I screwed it all up with the GKSU command or perhaps the sudu?
It definitely seems as if I've lost any and all permissions.