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I am trying to install 64 bit Windows 8 on my Mac Machine (Mountain Lion OSX) using a USB as a boot drive. For some reason bootcamp requires atlesst a 8GB USB. I however only have a 4GB USB. Is there any way I can override the 8GB minimum considering the size of the ISO is only 3.3 GB?

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You could choose not to use Bootcamp I suppose. My suggestion just go out and buy the $9.99 8GB drive. – Ramhound Sep 17 '12 at 16:25
@Ramhound It's not the price I have a problem with. It's the inconvenience. – user117094 Sep 17 '12 at 16:34
Will Mac and Windows be on the USB drive, or just Windows? – mcandre Nov 4 '12 at 4:38

The reason why bootcamp insists on a larger USB pendrive is that windows 8 will not fit on a 4GiB volume.

I know that you already mentioned that your iso is 3.3GB. However installing windows is not just copying an iso. It will copy and uncompress files. Even ignoring optional files like the pagefile and the hibernate files (neither of which are on the iso) your actual i disk requirements will be in excess of 3.3GB.

That is not a problem as long as they do not exceed 4GiB. However a quick search shows that about 8GiB of space is needed after installation.

Disk space needed for windows 8: (source)

  • x32 (on the DVD 2,9 GB, after installation on the hard disk 6,6GB +)
  • x64 (on the DVD 3,6 GB, after installation on the hard disk 8,2GB +)

Summary: It will simply will not fit on a 4GB volume.

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Assuming only Windows will be on the USB drive, simply use the Windows 8 installer to install Windows 8 on the USB drive.

When the computer reboots, hold the Option key to choose whether to boot Mac or Windows.

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