Hard drive is not detected at boot menu

[baahkenneth6]

My hard drive works when connect to a different machine but when connect to the asus laptop it does not show on the boot menu for installation

 

[Hoetan]

I'm guessing you are talking about an external hard drive with a USB connection, yes?

You can not use external HDDs with a USB connection as a boot drive, or find it in the BIOS at all. It is a USB device and the computer will not detect it as a STORAGE device. The only storage devices in your laptop are the HDD/SSD connected via SATA.