i have installed ubuntu 12.04 in lenovo G580 laptop. after installed successfully restarted my laptop. "grub not found" massage appeared when ever pressed power button. i reinstated again and installed "grub" by using ""so i realized something problem than removed "F12" function key. now also same error massage appearing when ever i pressed power button. finally i deleted 12.04 version than installed 13.04. even now also same error massage appearing.
now i am realizing the grub which i installed is making some problem. how can i remove this grub.
My system windows 7 OS also. previously both were working good. help me