cant boot a new operating system

[computer girl]

i am unable to boot a new operating system into my laptop . when i put a bootable pendrive and restart my pc and press boot button .the screen flashes once and shutdowns .i have samsung laptop . please help

 

[JeckeL]

Are you pressing F12 during startup to access the boot select menu? Press the power button to turn the laptop on, and immediately start pressing F12 repeatedly. If it brings up the boot menu select removable device. If it doesn't bring up the boot menu try holding F12 BEFORE powering the laptop on, and continue holding F12 until the boot menu appears

 

[computer girl]

in my laptop F9 is to access boot menu. but the problem is when i press it a black screen appears and it shutdowns .i have booted my laptop just 2 months ago .it was working fine then .is it because i have installed windows 10 technical preview ?