A Windows installation USB lets you install or reinstall Windows on any compatible computer. If you only have access to a Mac, you can still create a fully bootable Windows USB using tools designed for macOS.
This guide walks you through:
The tools you can use on a Mac to prepare a bootable Windows USB
How to format the USB correctly in macOS
How to write the Windows ISO file to the USB so it becomes bootable
What to do after the USB is ready
Step 1: Format the USB Drive on macOS
Open Disk Utility.
Select your USB drive in the left column.
Click Erase.
Choose the following:
Format: MS-DOS (FAT)
Scheme: Master Boot Record (MBR)
Erase the drive to apply the format.
Step 2: Install WinDiskWriter
macOS cannot write Windows ISO files directly using standard tools. Instead, use this verified open-source tool:
Download the latest
.dmgrelease.Open the file and drag WinDiskWriter into Applications.
Launch the app.
Step 3: Write the Windows ISO to the USB
Open WinDiskWriter.
Select your Windows ISO file.
Select the USB drive you formatted earlier.
Click Write and wait until the process completes.
This creates a fully bootable Windows installation USB.
Step 4: Install Windows on the Target Computer
Insert the USB into the Linux or empty computer.
Power it on and open the boot menu (often F12, F10, ESC, or DEL depending on the manufacturer).
Select the USB as the boot device.
The Windows installer will start.
Follow the on-screen steps and complete the installation.
Troubleshooting
If the computer doesn’t detect the USB, try a different port (USB-A often works best).
If the USB doesn’t boot, reformat and rewrite it.
Make sure Secure Boot is disabled if the installer does not start.