4 Replies Latest reply: Sep 25, 2009 3:49 PM by The hatter
dbs Level 2 Level 2 (155 points)
Hi,
I recently bought a 32 GB USB thumb drive. I was able to install a full copy of SL on the drive and use it to boot several different Macs in my household -- it's a little slow, but it works fine. The procedure was dead simple -- format the drive and away you go.

I cannot, for the life of me, figure out how to do the same thing with Boot Camp/Windows, i.e. install a copy of Windows on the USB thumb drive such that it will boot and run on a Mac.

I read somewhere else here that it isn't possible -- that Boot Camp can only run on an internal drive. I guess my question is: if all my Macs can install and boot OSX from an external USB drive, why isn't it possible to the same with Windows?

(As I type this it occurs that I didn't try booting the Mac from the USB drive, partitioning the thumb drive in Boot Camp and installing Windows from there. It would be pretty slow going, but maybe that's a solution?)

Thanks for any/all illumination!

MBA 1.86/SSD, 20" iMac G5, 15" MBP Santa Rosa, iPhone 8GB, Mac OS X (10.6.1)
  • 1. Re: Boot Camp install of Win 7 TO USB external drive?
    Fortuny Level 7 Level 7 (21,415 points)
    Hi dbs,

    by design courtesy of Microsoft Windows is not meant to be installed on external devices (harddisks or USB-sticks).
    Apple just strictly accepts this rule.

    However, there are solutions to be found on the internet for installing Windows XP and/or Vista onto external devices, so it might only be a matter of time before a solution for W7 is out.
  • 2. Re: Boot Camp install of Win 7 TO USB external drive?
    The hatter Level 9 Level 9 (58,880 points)
    The rules are in the BIOS and motherboard, not in Windows per se. Some boards like Intel's own DX58SO has two SATA ports on the motherboard that are treated same as any internal SATA port.

    Like the ODD ports on some Mac Pro models that OS X uses.

    But we don't have the luxury of what our BIOS does or does not offer or support.
  • 3. Re: Boot Camp install of Win 7 TO USB external drive?
    dbs Level 2 Level 2 (155 points)
    From my days using ThinkPads (long, long ago) I remember doing flash updates to the BIOS. The updates came from IBM, not Microsoft (so I assume the BIOS was hardware-based, not software (i.e. Windows o/s) based.

    That suggests (to me, anyway!) that something in the Mac motherboard prevents installing Windows on an external drive (but allows OSX to be so-installed).

    I've also read the Macs use "open firmware" instead of BIOS and that open firmware is, to some degree, programmable (as in programmable to allow Win to boot from a USB drive).

    Am I on the right track or am I completely, totally, wrong?! (I'm 'way over my head here).
  • 4. Re: Boot Camp install of Win 7 TO USB external drive?
    The hatter Level 9 Level 9 (58,880 points)
    Intel Mac uses EFI.

    The BIOS update comes from the motherboard vendors.

    Open Firmware was PowerMac only.