Creating a BIOS bootable USB Drive with a .iso file

Apr 24, 2020
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Hi Everyone, thanks for coming to the thread.

I have a macbook and I'm getting a brand new computer I will assemble myself.
I'd like to install windows os on it and that requires creating a bootable usb drive with an active primary partition and moving the .iso file there.

I don't have much of experience in these matters myself which is why I seek your help.

So far I've:
Erased the USB in the disk utility and rebooted it with MS-DOS(FAT-32) formatting, and GUID partitioning scheme.

In the terminal I used sudo fdisk commands to access the new created partition and set it active using

sudo fdisk -e /dev/rdisk2
disk2 being the usbdrive
f 1
f for activating 1 for the only partition on this usb drive, which I will use for the .iso file

I then ejected the drive and put it back in, is that enough to reboot it?

When I use get info on the partition it still says bootable - no does it mean I did something wrong or does it only refer to it being not bootable on a macosx (since its FAT32; GUID it might not be)

I will use an external application (Etcher) to write the .iso file on the new partition.

Any Macintosh pros out there can you confirm I did everything correctly?

Thanks for reading,



Cory Cooper

May 19, 2004
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Hello and welcome.

It sounds like you are building a Windows PC? If so, I don't have much experience with Windows, Windows ISOs, or Etcher.

-Are you building a Windows PC?
-What OS is the ISO file?
-Is the USB drive a flash drive or a hard drive?


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