I had installed Ubuntu (current version: 11.xx) alongside Windows Vista. Now I formatted the Ubuntu partition & merged it with another partition (without thinking, obviously). Now, when I restart the computer, GRUB probably tries to find the old partition (which does no longer exist) and says: error: no such partition. grub rescue> Now I dont know what to do (I'm a total beginner). I tried to re-install Ubuntu on the newly formatted partition but this won't work, because after removing the install-usb (which I am said to do during installation) I find the above error-message again. I guess I need some way to reconfigure grub OR to reinstall grub/ubuntu (on the newly formatted partition) OR to reinstall the windows boot manager (without reinstall. Windows), but I have no idea how to do either of these things.