There aren't many options at that level. Burn a fresh USB, use a different way to burn the usb so you have a different dos flavor, try a different version of megarec. Throw it in a different box.
Short of touching the box, it is pretty hard to help on this low level stuff. But it isn't unusual for mobo's to have their personalities and quirks. Not many of that older intel board around here. You haven't hit the card yet, you have a DOS problem to fix. Rufus is an extremely common known good quantity, but there are other options. Here is
another easy way to write a bootable usb.
You'll probably have to just 'work through it' but we'll help where we can.