How to create a bootable USB Windows OS using Mac OS X

OK. Here are some instructions from Gizmodo that will put the ISO onto the flash drive with a Mac... they won't make it bootable though... read on...

1. Open a Terminal (under Utilities)

2. Run diskutil list and determine the device node assigned to your flash media (e.g., /dev/disk2)

3. Run diskutil unmountDisk /dev/diskN (replace N with the disk number from the last command; in the previous example, N would be 2)

4. Execute sudo dd if=/path/to/downloaded.iso of=/dev/diskN bs=1m (replace /path/to/downloaded.iso with the path where the image file is located; for example, ./windows7.iso)

5. Run diskutil eject /dev/diskN, and remove your flash media when the command completes (this can take a few hours on slower drives)

Now... after you read all that, on the Gizmodo page it says that if you want to make it bootable you should use a utility called Live USB helper they link to (which isn't there any more) and use a Mac mounting tool (which isn't there either!) to force the ISO to mount on the Mac so you can copy the files over. So... that article may prove useful, but probably not. I can find other copies of Live USB helper out there, but they are all Windows executables.

One method that will work is to swap the hard drive out of the PC and into the Mac. Put your Windows 7 installation disc into the Mac optical drive, and install Windows 7 on that drive. Once it is up and running (don't worry about drivers yet), follow these steps.

1. Run Command Prompt as administrator
2. Type to Command Prompt: %windir%\System32\Sysprep\Sysprep.exe, and hit Enter
3. In sysprep dialog that opens, choose “System Cleanup Action” as “Enter System Out-of-Box-Experience (OOBE)”, select “Generalize”, and select “Shutdown Options” as “Shutdown”. Click “OK”
4. Sysprep generalizes now your Windows 7 setup and shuts down your computer. Do not run any other programs during this phase!
5. Remove the drive from your Mac. Put it back into the PC.
6. Boot the PC from sysprep generalized hard disk. You will notice Windows booting as if it was the first boot after installation, installing default and updating registry. One or two reboots are needed, depending on your system specifications
7. When Windows finally boots up, you will need to enter all information as if this really was a new, fresh installation

All that is from here, but it applies in this situation a well, since you would be moving a Windows 7 installation from one computer to another. Considering that trying to make a Windows bootable USB stick with a Mac requires tools that either don't exist any more or are not being developed any more... this second method will most likely prove more dependable.

Assuming you have burnt your Windows CD into a ISO file with the tools like:
http://burn-osx.sourceforge.net/Pages/English/home.html

1. Jump into a folder here http://sourceforge.net/projects/unetbootin/files/UNetbootin/
2. Get the latest version of zip archive with the keyword "mac" in the filename.
3. Download and open it up on your Mac OS X desktop.
4. On Unetbootin interface, choose [Diskimage]->[ISO] and then select the Windows ISO file on your local hard drive.
5. Select the right USB Drive and then click [OK] to start writing ISO data onto your USB drive.


Once done, you're ready to boot your computer with this bootable USB drive, like a DVD installation disk.

You could also use VirtualBox on your Mac and install Windows quickly, then use Windows to create the media for the PC. You just need to allow windows to read from the USB port.

Microsoft published free to use Windows virtual machines for Internet Explorer testing purposes, but you can also use them to create a bootable USB stick.

To allow Windows to read from the USB port you'll need to install the VirtualBox Extension Pack. Then you can enable the USB 2.0 (EHCI) Controller in the virtual machine's settings (Ports -> USB).

Then when you insert the USB stick, it will probably first be detected by OS X, and since only one OS at a time can acces the port, you should eject it in OS X. Then it should automatically show up in Windows. If it's not, try to click the USB cable connection icon at the right bottom in the virtual machine. The USB port should be listed there and when you click it it should be mounted.

Then you can use a tool such as Rufus to create a bootable USB stick.