i have a toshiba sattilite laptop and it was duel booted with windows 7 and ubuntu 12.04 i tried to uninstall Ubuntu so i deleted what i thought was the Ubuntu partition and no when i turn on my laptop it goes to a black terminal like screen and it sais error no such partition then under it it sais grub rescue> i have a windows 7 recovery disc and the ubuntu 12.04 disc but i dont no how to boot into them becaus it just goes to this screen