Windows can't read or write Mac disk formats natively, so making a macOS bootable USB from a Windows PC takes a third-party tool. The most reliable route is TransMac: format the drive for Mac (GPT scheme), restore the macOS DMG onto it, then boot the Mac from USB — Option key on Intel Macs, hold the power button on Apple Silicon. This guide is adapted from the full Indonesian tutorial.
What you need
A USB 3.0 flash drive (32 GB recommended, especially for macOS Tahoe), a macOS DMG file, TransMac (15-day free trial), and a Windows PC with admin rights. Everything on the drive gets erased, so back it up first.
Getting a legal DMG
The hardest part is getting a legal DMG. Apple doesn't offer direct DMG downloads for Windows. The legitimate routes are downloading the installer from the App Store on a Mac, or building a DMG from Apple's own servers (e.g. the GitHub project macos-iso-builder, which pulls straight from Apple). Avoid pirated DMG sites — besides the licensing issue, the files are a common malware vector. One trap: if your "installer" is only tens of megabytes, it's a stub downloader, not the full installer. A real DMG is over 10 GB.
TransMac steps
Run TransMac as administrator, right-click the drive and choose "Format Disk for Mac" (this converts the usual MBR scheme to GPT, which Macs require for external boot media), then right-click again and choose "Restore with Disk Image", pick your DMG, and wait 15–25 minutes on USB 3.0 (30–60 minutes on USB 2.0). Eject safely when done.
Free alternative
Rufus can write a DMG with a GPT scheme and UEFI target, but success rates for full macOS DMGs are spottier than TransMac. If you can borrow a Mac, Apple's own createinstallmedia command is the most reliable path of all.
Booting from the USB
On Intel Macs, power on while holding Option until Startup Manager appears. On Apple Silicon, shut down, then press and hold power until "Loading startup options" shows. Don't mix them up. Intel Macs with the T2 security chip may also need external boot enabled in the Startup Security Utility (Recovery Mode > Utilities).
Verified GPT check and capacity math
I verified the GPT part myself in a VM: a Python script built a 64 MB disk image with a protective MBR (partition type 0xEE) plus an "EFI PART" GPT header and two partitions (EFI + installer), then read it back and confirmed every field. The capacity math matters too: a "16 GB" flash drive holds only 14.9 GiB, so it cannot fit the ~15.8 GB Tahoe installer — use 32 GB.
Full Indonesian tutorial with troubleshooting and FAQ: https://www.miftahulrizki.eu.org/2026/10/cara-membuat-flashdisk-bootable-macos.html
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