Hi. I have a little problem. I have installed Windows 7 on my laptop and Ubuntu 11.10. I want to uninstall 11.10 and install 10.10, so i formated partisions of 11.10 and install there 10.10, but the grub menu doesn't show any list of operating systems when i start my computer. The grub show me "no such partitions" and grub's command line. I can't run any system. Please help!