Whn you need your computer to boot from USB or CD/DVD drive, you mush disable secure boot option, while you need to enable secure boot to make windows 8 boot correctly.
1. Power on HP laptop, and then press F10 key repeatedly until Computer Setup Utility starts.
2. Use <- and -> key to selcet Security menu, and then use Up and Down key to select Secure Boot Configuration and then press Enter.
3. When Secure Boot Configuration warning appears, press F10 to continue.
4. You can use the up and down arrow keys to select Secure Boot , then use the left and right arrow keys to change the setting to Disable or Enable. Use the same opeartion to Disable or Enable Legacy Support.
5. Press F10 to save the changes.