I am using an Asus Z170-P D3 in my first PC build, and when I turn on my computer, the monitor shows the POST screen. This is what I would expect, as I have not installed any operating system on the machine. When I try to enter the BIOS by pressing delete on my keyboard, as I am instructed to on the monitor, nothing happens. I have tried using two USB keyboards plugged into every USB port, and a PS/2 keyboard. I decided to test whether any of the rear panel IO was working by moving the connection to the monitor from the graphics card to the ports on the motherboard itself, and this did not work. I do know, though, that power is getting to the USB ports, as when I plug a portable charger into it, it lights up and begins to charge. I can't imagine what could be causing this problem. Any advice would be appreciated.