I have an old Windows corporate machine that won't start or complete a repair to its hosed Windows installation. I want to rebuild it with Windows 10, but I can't find a way to effectively create a bootable USB from my Mac since the ability to do so within Bootcamp was removed with Mojave OS.

Most of the online instructions involve buying some form of suspicious software to do this, but I did find one website that walked me through the process of expanding the Win10 ISO file into its own drive on the Mac, and then copying the contents of that drive to the USB - I tried this, but the result was the Dell machine would not boot no matter what I tried with the BIOS.

Are there any reliable, free utilities out there that would take an ISO file and burn it to a USB stick as bootable media in the BIOS (not UEFI)?