keep holding F2 until the UEFI screen (aka BIOS) pops up. Press and hold F2, then power on laptop.To do this on my Acer: (firstly, laptop has to be powered off).
it doesn't care if I have a windows repair CD, or USB recovery flash drive plugged in. With UEFI (and secure boot) enabled, my computer is ONLY looking for the operating system on the internal HDD (or SSD).
if you hear clicking, then your HDD is more than likely toast. and these make a noticeable sound when they are running (smooth high pitched whirling). More often than not, these are standard with many factory systems. Almost like a high-tech record player there's a spinning platter that stores the data (the vinyl), and a read/write arm with a magnetic head that access the platter (not unlike the tonearm and cartridge-needle on a record player). these are traditional hard drives with mechanical moving parts. they are fast! they tend to be included with higher end systems or as aftermarket upgrades. Think of it like how a usb flash drive works. Even if they fail, there will never be any clicking sounds, vibrations. there are no mechanical movements in these hard drives. here are some important points that need clarifying. Some misleading and incomplete info in a few of these replies.
