Unfortunately, I don't have any idea how to repair your system to make it bootable, I can only suggest the following:
1) google up the command(s) to run from console to copy your data files to CD/DVD.
2) make a folder (or more than one in needed) and fill each folder with a CD/DVD worth of files.
3) copy those files to media.
4) use your file manager and verify that you can see those files on the media.
5) maka a clean install of the latest Ubuntu.
6) copy your data files back to hard drive from media.
You will need to use a small disto that can be loaded entirely into RAM so that you can use the CD/DVD drive for copying your data files.
Boot the distro then remove the disk from the drive. Mount the partition that contains your data files and copy them to media.
Last edited by bigrigdriver; 09-25-2011 at 08:18 PM.