I backed up my important data. Then upgraded to 12.04 LTS through update manager.
The process didn't work. I managed to get 12.04 on what was left of the drive space (about 35 GB), but now I have a 81 GB file system showing that I can't access. It shows a lost+found folder in it, but I can't open it
"you do not have the permissions neccessary to view the contents of 'lost+found'"

Is there a way to find out if the file system has been wiped?

Please be advised that I use Ubuntu because I love open source. I do not know how to use it properly and therefore need clear instructions.