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?

  • Put Win7 64 on the Mac. Make a Win7 32 USB installer on there. Use that to recover the PC. – Tetsujin Jan 16 '18 at 7:18
  • @Tetsujin you mean first format my current macOS with Win7? That cannot be an option... Any other method? – Homer Jan 16 '18 at 7:29
  • Boot Camp. How else were you going to do it? You need Windows to make a bootable Windows installer for another machine. Boot Camp can install from just the iso, but a Windows PC can't. You need the Media creator tool from Microsoft... which runs on Windows. – Tetsujin Jan 16 '18 at 7:34
  • @Tetsujin So I'm going about this wrong. Thanks for the notice. I'll look for a public Windows computer to use. How would you suggest that I create the bootable USB from a public windows computer? I have the ISO, et al., in the drive. – Homer Jan 16 '18 at 7:57
  • support.microsoft.com/en-gb/help/15088/… I'm not sure of the exact procedure these days, as MS has put the structure behind a password wall & I don't have any spare Win 7 keys any more. – Tetsujin Jan 16 '18 at 8:01

Basically, you can use your Mac to create a USB flash drive installer for use on a PC. The steps are given below.

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

  7. 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.

  1. Click on the image of a USB flash drive on the bottom of the virtual machine window. Note the devices.
  2. Insert the flash drive in a USB port.
  3. Repeat step 1. The flash drive is the new item in the list. Usually something cryptic. The item may be grayed out.
  4. 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.

  5. 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.

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  • I've downloaded all the files. I am now running the Windows virtual machine with the very ISO that I intend to use to make the bootable USB. Meaning, when starting the VM, I've pointed it to the ISO on my USB. So I followed step 5 and am attempting step 6, but I cannot find any way to access the USB from within the Windows 7 VM--that is what you mean, yeah? To access the USB from the VM and use the creation tool from within? On the VM's "Ports" settings, I've added all the available USB device filters, but I cannot seem to access them from the VM. – Homer Jan 17 '18 at 12:14
  • I have started the VM using 32-bit and 64-bit ISOs. I ultimately need a 32-bit bootable windows to use on the old computer I am trying to restore. With the VMs however, when I start the 32-bit ISO, I don't receive any feedback regarding the plugged in USB. When I start the VM with the 64-bit, Windows will try and install the "device driver software". But the "USB Mass Storage Device" will show a "X Failed" and not install. – Homer Jan 17 '18 at 12:37
  • It does take a lot of practice to access a physical USB flash drive from VirtualBox. I updated my answer. – David Anderson Jan 17 '18 at 13:21
  • Thank you. Got it to boot to the install window. Although it'll never pass this point and instead return me back to the very first install tab. I believe this is more an issue with my ISO and beyond this question. Much appreciated, sir. – Homer Jan 17 '18 at 17:21

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