@Paul Black, Those Sysinternals tools are way out of my league, I think only Aliens use those lol.

I just booted the Hirens from a UEFI Machine that was set as Legacy, so the thing boots both, as some of your already knew I'm sure.

Just found a really good use for this tool. I was trying to fix/diagnose a computer that is acting really weird. It has no HDD or OS on it, but wanted to see if I could get it working. I was trying to boot from Linux to see if all the hardware was good. I then saw that I could not get the F12 Temp Boot Order to come up no matter what I did. Reviewed all the BIOS Settings etc. I was eventually able to boot from a USB and DVD, but not in the usual way I'm used to. Had to press F1 After setting the boot device and rebooting.

The only weird thing the computer is doing aside from the weird BIOS issue, when you plug it in from a cold start, one of the Fans come on briefly. It's a desktop, and I reseated all the connectors on the MB and the RAM.

I thought I would try to Flash the BIOS as it was not acting correct IMO. The computer has no OS, and no HDD. I was in a situation where I did not want to use one of my Good USB Drives to Flash the BIOS from a DOS Prompt. I thought about Hirens as I was debating how to do this, SUPER, just booted Hirens and plugged in a spare junk USB, 256MB, that someone gave me with the BIOS exe on it. Clicked the BIOS exe and away it went, installed and verified!