It automatically splits the large ISO file into small parts so the Windows installation files can be sit on a FAT32 partition, which is the only working file system supported by Mac for Windows install. If you are using a newer Windows 10 ISO (after version 201809), then UUByte ISO Editor is the best app for creating a bootable USB on Mac. I managed to create several bootable Windows 10 USBs on Mac (Mojave, Catalina and Big Sur) in recent years. I had to create a Windows partition on my hard drive and boot into that to make a functioning boot drive. The ExFAT formatted drive with Windows ISO did not work as a bootable drive. Will report back if I run into any issues. All this said, I have yet to actually use this drive to INSTALL Windows as I'm building the computer tomorrow. I just did this with a Sandisk 32GB drive and it worked perfectly. Select 'ExFAT' in the format dropdown and confirmĪfter this process you are able to move larger files into your USB drive.Select drive you want to be the boot drive.Here are the steps! For reference I'm running Mac OS Monterey (v12.0.1) The easiest thing to do is just to reformat your drive to 'ExFat' using Disk Utility. Sorry if this is a breach of etiquette (commenting on an old thread!) You don't need to download any new software to do this, everything is already included in current Mac OS.

In case anyone stumbles onto this thread I'm going to give what I believe to be the easiest solution to this problem.

Bootable disk utility mac