I have installed Ubuntu 12.04 in Lenovo G580 laptop. After installed successfully restarted my laptop. "grub not found" message appeared when ever pressed power button. I reinstalled again and installed "grub" by using ""so I realized something problem than removed F12 function key. Now also same error message appearing whenever I pressed power button. Finally I deleted 12.04 version then installed 13.04. Even now also same error message 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