Format Thumb Drive Mac Command Line



Most new PCs don't come with DVD drives anymore. So it can be a pain to install Windows on a new computer.

Luckily, Microsoft makes a tool that you can use to install Windows from a USB storage drive (or 'thumbdrive' as they are often called).

But what if you don't have a second PC for setting up that USB storage drive in the first place?

Thatโ€™s it, you know how to format a USB drive on Raspbian Desktop ๐Ÿ™‚ If you donโ€™t already have a partition on your drive, itโ€™s the same process (as simple as right-click new) Raspbian Lite and command line. As usual, the Raspbian Lite way is less straightforward ๐Ÿ™‚ Find the virtual drive name. Because your USB size is more than MAX Volume size of FAT. FAT/FAT16: Max volume size 4GB, Max file size 2GB. FAT32: Max volume size 2TB, Max file size 4GB. ExFAT: Max volume size 128PB, Max file size 16EB. It mean if your USB flash drive is 8GB or more, it will not support FAT format. So what you need is resize it to 4GB. The terminal command line in Mac can be used to format USB devices. This method can be used when you are unable to format the USB device through Disk Utility. As always, having a backup option will save you when plan A fails for some reason. Let us go through the exact steps in formatting your USB drive to FAT32 on Mac using the command line.

In this tutorial we'll show you how you can set this up from a Mac.

You can download the ISO file straight from Windows. That's right - everything we're going to do here is 100% legal and sanctioned by Microsoft.

If you want an English-language version of the latest update of Windows 10, you can download the ISO here.

Format

If you have a relatively new computer, you probably want the 64-bit version. If you're not sure, go with the 32-bit version to be safe.

If you want a non-English-language version of Windows, or want to get an older update version, download the ISO here instead.

The ISO file is only about 5 gigabytes, but I recommend you use a USB drive with at least 16 gigabytes of space just in case Windows needs more space during the installation process.

I bought a 32 gigabyte USB drive at Walmart for only $3, so this shouldn't be very expensive.

Stick your USB drive into your Mac. Then open your terminal. You can do this using MacOS Spotlight by pressing both the โŒ˜ and Space bar at the same time, then typing 'terminal' and hitting enter.

Don't be intimidated by the command line interface. I'm going to tell you exactly which commands to enter.

Open Mac Spotlight using the โŒ˜ + space keyboard shortcut. Then type the word 'terminal' and select Terminal from the dropdown list.

Paste the following command into your terminal and hit enter:

diskutil list

You will see output like this (note - your Mac's terminal may be black text on a white background if you haven't customized it).

Format Thumb Drive Mac Command Line

Copy the text I point to here. It will probably be something like

/dev/disk2.

Next format your USB drive to Windows FAT32 format. This is a format that Windows 10 will recognize.

Note that you should replace the disk2 with the name of the your drive from step 3 if it wasn't disk2. (It may be disk3 or disk4).

Run this command using the correct disk number for your USB:

diskutil eraseDisk MS-DOS 'WIN10' GPT /dev/disk2

Then you'll see terminal output like this.

Format Thumb Drive Mac Command Line

This will probably only take about 20 seconds on a newer computer, but may take longer on an older computer.

Note that for some hardware, you may instead need to run this command, which uses the MBR format for partitioning instead of GPT. Come back and try this command if step 7 fails, then redo steps 5, 6, and 7:

Now we're going to prep our downloaded ISO file so we can copy it over to our USB drive.

You will need to check where your downloaded Windows 10 ISO file is and use that. But your file is probably located in your ~/Downloads folder with a name of Win10_1903_V1_English_x64.iso.

Format thumb drive mac command line windows 10

hdiutil mount ~/Downloads/Win10_1903_V1_English_x64.iso

Update April 2020: One of the files in the Windows 10 ISO โ€“ install.wim โ€“ is now too large to copy over to a FAT-32 formatted USB drive. So I'll show you how to copy it over separately.

Thank you to @alexlubbock for coming up with this workaround.

Mac

First run this command to copy over everything but that file:

rsync -vha --exclude=sources/install.wim /Volumes/CCCOMA_X64FRE_EN-US_DV9/* /Volumes/WIN10

Then run this command to install Homebrew (if you don't have it installed on your Mac yet):

/usr/bin/ruby -e '$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)'

Then use Homebrew to install a tool called wimlib with this terminal command:

brew install wimlib

Then go ahead and create the directory that you're going to write the files into:

mkdir /Volumes/WIN10/sources

Format Thumb Drive Bootable

Then run this command. Note that this process may take several hours, you may see 0% progress until it finishes. Don't abort it. It will use wimlib to split the install.wim file into 2 files less than 4 GB each (I use 3.8 GB in the following command), then copy them over to your USB:

wimlib-imagex split /Volumes/CCCOMA_X64FRE_EN-US_DV9/sources/install.wim /Volumes/WIN10/sources/install.swm 3800

Once that's done, you can eject your USB from your Mac inside Finder.

Congratulations - your computer now should boot directly from your USB drive. If it doesn't, you may need to check your new PC's BIOS and change the boot order to boot from your USB drive.

Format Thumb Drive Mac Command Lines

Windows will pop up a screen and start the installation process.

Format Flash Drive Mac Command Line

Enjoy your new PC, and your newly-installed copy of Windows.