How to support 32-bit windows installation on boot camp I'm attempting to make my USB a bootable windows 7 installation. I have the Windows 7 installation ISO image and related files. When I attempt to format my USB with the files, I receive the error: Boot Camp only supports 64-bit Windows installation on this platform. Please use a ISO file for 64-bit Windows installation.  

My ultimate goal is to make the USB bootable with a new Windows 7 install from within my mac, and then booting my old Windows Vista computer with the fresh install.  

How might I get this to work?
Basically, you can use your Mac to create a USB flash drive installer for use on a PC. The steps are given below.


Install Virtual Box. This is free software.
Install Virtual Box Extension Pack. This will give virtual machines access to the USB ports.
Create a Windows virtual machine. Do not activate.
Download the flash drive creation tool. This download website is very slow. Be patient.
Put the Windows iso file and the flash drive creation tool on the flash drive.
Copy the iso and creation tool from the flash drive to the Windows virtual machine main drive.
Use the creation tool to transfer the iso to the flash drive.


If you need a better explanation of any step, let me know.

Advice on VirtualBox and Flash Drives

Try these steps.


Click on the image of a USB flash drive on the bottom of the virtual machine window. Note the devices.
Insert the flash drive in a USB port.
Repeat step 1. The flash drive is the new item in the list. Usually something cryptic. The item may be grayed out.
If the item is grayed out, then you must unmount the flash drive. You can do this from the Disk Utility application, but sometimes this fails to work. If you use the Terminal application, you can enter the command diskutil list before and after inserting the flash drive in the USB port. The added disk is the one that must be unmounted. Here, I will assume this is disk1. The command to unmount the flash drive would then be as shown below.

diskutil  unmountdisk  disk1



  Note:  Sometimes you have to wait a few seconds before the status of a flash drive changes. For example, you can unmount a flash drive, but the item may remain grayed out in the VirtualBox list for several seconds.

Click on the image of a USB flash drive on the bottom of the virtual machine window. Select the flash drive. If it is still grayed out, then you must repeat step 4.



  Note: I would not mess with the VM "Ports" settings or USB device filters In fact, I have never figured out what the device filters are for.