i have formatted my laptop completely and installed Ubuntu 14.4 after installation Ubuntu is not booting directly i have to put the pen drive(which has Ubuntu 14.4 live cd) every time on start up and press f4 which is for recovery after booting if take the pen drive then no problem its working normally my laptop is Samsung np370 with Intel i5 3rd gen processor with 6gb ram and 1tb hard disk please help me