Hi
If you can't get the computer to boot at all, and if you computer still has a recovery partition you should be able to restore it to factory settings.
Check the manufacturers website to see how you access it.
If you have stuff you don't want to lose on it, you can try creating a Ubuntu disk on another computer and using it to boot your computer.
Once booted into Ubuntu you will be able to backup the data that you want to keep, i.e. favorites, photos, address books, music, etc. before doing the reset.
http://www.ubuntu.com/download/desktop
My Ubuntu DVD has booted pretty much anything I've tried to boot with it.
Mike
Here's what I found...
● Turn on or restart the computer, and then press esc while the...