windows - Partitioning a bootable Flash drive

  • mmc

    Is it possible to have a 2 partition Flash drive that looks like the following:

    • A partition that is bootable to OS X (this will require a GUID partition table)
    • A second partition formatted either FAT32 or NTFS that is readable on both OS X and various flavors of Windows

    I have set up a disk using Disk Utility on the Mac, and it boots fine with a second FAT32 partition... but Windows does not see it. Any flavor of Windows wants to format the entire drive.

    Has anyone done this, and if so, can you explain the steps you followed?

    EDIT: Making it bootable is no problem. I have that. I'm wondering how to make the second partition on a Flash drive visible to Windows. It's possible that the "second partition" is the problem, and I need Windows to be first, and HFS to be second. I'll try that tonight.

  • Answers
  • Chris Nava

    Unfortunately, the windows accessable partition must be the first partition on a thumb drive or windows will not mount it. Linux installs can get around this limitation by putting the bootloader configuration files on the windows partition and everything else on the second partition. I'm not sure if you can do this with Mac though. My Mac is to old to try (as it is PPC based.)

  • mcandre

    The Geniuses at the Apple stores use external USB drives that boot to Mac OS X. So it's possible.

    iHackintosh shows you how. rEFIt helps to make drives bootable for Mac and Windows. You'll need something like it in order to keep the two partition managers (Mac and Windows/Linux) in sync.

  • Related Question

    windows - How do you partition a USB Thumb / Flash Drive?
  • Omar Shahine

    Out of the box, Windows will not allow you to partition a USB Thumb / Flash Drive. How can you do this?

    In case anyone is wondering Why you would do this?

    It's interesting in the case of a BitLocker ToGo drive where you can take a large thumbdrive (like 4 or 8 GB) and format a small amount of the drive to be used normally as a Fat32 drive and leave the remaining partition encrypted using BitLocker. This allows you to keep some non secret data on the unencrypted partition(like portable apps).

  • Related Answers
  • William Hilsum

    Just use your favourite partitioning tool - Either Disk Management on Windows, or Gparted on *nix, or other - They should all understand USB flash drives, and you simply partition as if it was any other hard drive.

  • Brent

    Out of the box, Windows Vista/7 allows the partition of an USB drive. The command is diskpart.

    What is this, are you posting questions and answering them?

  • valjaer

    You can use Windows cmd.exe: run it as administrator and use console utility diskpart.exe to partition the drive. Manual:

  • Omar Shahine

    One way to do this is using a tool called BootIt. this tool removed the removable bit on the thumb / flash drive and allows you to partition the drive.

    I'm sure there are better ways to do this, but this is the only one I can think of.

  • Pops

    Windows must be able to recognize the flash drive as a "fixed disk."

    This is accomplished by either flipping the removable bit (which doesn't always work), or modifying the cfadisk.c, and .inf files, assuming you're on XP. (You must know how to code for the latter.)