USB or DVD Boot Drive Determination/Selection

I have downloaded and successfully installed Windows 10 version 1703 including the recent update. Now, I need to download and create Installation Media and note I need to determine whether this PC is setup to boot from USB drive or DVD drive. Either advancing age or brain cramp-but my recollection fails. How do I determine whether DVD or USB is set as boot drive? Does one have advantage over the other? I there any reason for both to be designated as boot drive?

Well that would be set in you BIOS, if you do a lot of booting with either USB or DVD it is helpful to have either or both selected as firs choice boots. Otherwise there is not point in having either selected as first or anywhere in the booting sequence. There a ways to get a USB or DVD to boot first using a key or key sequence on boot up. On my computers some use the Esc Key. So if I need to boot say my Macrium Reflect Bootable recovery media on USB Stick. On boot up I'll spam the Esc key and up pops a boot menu where I'll select UEFI USB or UEFI DVD or USB or DVD to boot from this boot. On others it might be F2 or Del or F8, you just need to learn which key it is for your computer.
So the answer for most people now days with relatively modern equipment no you don't need or want USB or DVD as first boot options

Welcome to TenForums @Abe Froman

You only need to boot from your USB or DVD intstall media if you want to do a clean install. How you do this varies from one manufacturer to the next, and on what type of BIOS you have. For some you need to enter the BIOS and change the boot order, others have a boot selection menu that you get to at boot time by pressing F12 (or similar). Check your manual for details.

For Dell I believe it's F12. You will need to boot from cold to get this option, so turn off fast start, or Restart the PC rather than use 'Shut down'.

Bree said:

For Dell I believe it's F12. You will need to boot from cold to get this option, so turn off fast start, or Restart the PC rather than use 'Shut down'.

You also get a full shutdown, bypassing Windows fast startup, by holding down the Shift key when you click on the Shutdown option of the power button menu.