Is the USB bootable?

Unfortunately I can't because my keyboard only powers on after POST.

Can you enter your bios and see if you can change the boot order, and put boot from USB as the first boot device?

It should be, I created it with the Windows 10 media creation tool for installing Windows on a new PC.

I also have my old Windows 7 recovery USB from Dell and it doesn't boot either.

I am assuming you are not seeing an F2 prompt during POST?

You're right, I'm not. Even when it worked, my system went from black screen to Windows screen without the usual F2/F12 prompt. 

Reason why I was asking is because the manual states that if you do see the F2 prompt, it initializes the keyboard.

So not seeing it would confirm it is not initializing the keyboard.

Would you happen to know which bios version your machine is running?

Sometimes it goes really quickly.  Plug a basic wired keyboard into the I/O shield of the motherboard on the back of the PC, push restart or on and immediately start hitting F12 even if you don't see any prompts.  If/when the boot menu pops up, select the USB drive and boot from your USB.  If you encounter issue, make sure USB is not disabled in BIOs. 

If all else fails direct it to load the option on restart to boot from your windows USB media before shutting down, in windows 10, under settings/recovery. 

I unfortunately have no idea what my bios version is... I never needed to enter the bios until now on this specific machine. 

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As for the other ideas lower down, I already used a basic wired keyboard (USB, not PS/2 since there is no PS/2 port) and I can't do anything in Windows since my HDD died and I'm trying to boot to USB to install Windows. 

I have a second machine available but sadly it's a laptop which limits my options (can't slave the drive to install Windows).