Anyone who knows me will know that I am a big fan of ubuntu (HTTP://www.ubuntu.com/), but yesterday, something terrible happened. Whilst trying to upgrade from version 8.04 to 8.10 it failed. First, it seemed to upgrade, but the keyboard and mouse didn’t work, then it crashed during install, and lastly, when I had decided to re-install 8.04 and go from there, it seemed to have installed perfectly but GRUB (the bootloader) gave “Error 15″ on bootup, which means it can’t find the system to boot. I write this from a livecd, worrying that I may never see my beloved ubuntu again.
This instructions in this post error 15 – Ubuntu Forums should help get GRUB to recognize the Ubuntu system again.
Unfortunately that post didn’t help, I ended up doing a complete re-install
(Sorry it took so long for me to reply, I’ve been meaning to for a while but kept forgetting and remembering just as I shut my computer down 
)