Hard drive problem

I was upgrading my Xubuntu to 7.10 and the power went out at a crucial moment. Now I can not get into Xubuntu via my hard drive. When I try, it gives me this message:

Quote:
[ 17.461087] Kernal panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Right now I am running Xubuntu off of the live CD. When running off the live CD, I seem to be able to acces the afflicted hard drive, but some files I cannot get to. I am particularly interested in getting into my desktop folder, but when I try, it gives me this message:

Failed to open directory "Desktop".
Permission denied.
I've tried going through the terminal in super user mode, but I cannot get into super user mode because I appearently do not have the correct password. When I try, it gives me this message:

su: Authentication failure
Sorry.
I would like to save the hard drive if I can. If I can't save the data, I'm willing to format and start over, but I would really like to save some files from the desktop folder that I desperately need. I have already saved many files in my home directory which does not give me the aforementioned message.

Once again, if someone can help me save the hard drive from formatting, that would be great. If not, I'd still be most greatful if someone could help me access my destop folder.

Thank you