I upgraded 9.10 to 10.04 and now it won't boot. The way 9.10 used to boot was after turning on the computer it would go through the bios screen and then a screen would come up and list both operating systems, Windows Xp and Ubuntu. XP would be highlighted and would normally boot if I did not change the highlighted area. If I changed the highlighted area to Ubuntu it would boot into Ubuntu 9.10. Now after doing the upgrade, it gets to the same screen with the two operating systems listed, but when I change the highlighted to Ubuntu an error message is briefly displayed and then it goes back to the screen that lists both operating systems. I think the error message says something like couldn't find Ubuntu, or something similiar to that. Windows XP runs fine when I highlight Windows Xp in that first screen, but I want to be able to run Ubuntu. I have Ubuntu on a secondary drive, but shouldn't it have rewritten the upgraded files on that same drive that had 9.10 on it? Please help!