Boot Camp issues

Discussion in 'Windows, Linux & Others on the Mac' started by BlueIS3, Sep 7, 2011.

  1. BlueIS3 macrumors newbie

    Sep 5, 2011
    I just purchased a 2011 MBA that I want to install Windows 7 on. Trying to use Boot Camp Assistant but getting stuck on the USB Boot Drive creation.

    Here's what I've gone through so far...

    Boot Camp Assistant asked for a Windows 7 Disk Image. I have a Windows 7 Home Premium DVD in an external drive.

    Used Disk Utility to create a dvd/cd disk image that I saved on my hard drive. I renamed the image it created to end with an .iso extension.

    Boot Camp Assistant recognizes the image and recognized my 4 GB USB flash drive as the destination. Boot Camp formats the drive but throws out an error: "your bootable usb drive could not be created".

    Any idea what's up?
  2. jdechko, Sep 7, 2011
    Last edited: Sep 7, 2011

    jdechko macrumors 68040

    Jul 1, 2004
    You can't just rename a .dmg file to .iso and hope that it would work. It's like renaming a .jpg to .doc and expecting everything to be just peachy. However, it is possible to convert a dmg to an iso.

    hdiutil convert /path/to/filename.dmg -format UDTO -o /path/to/savefile.iso
    From here.

    EDIT: Open up terminal (In the Applications/Utilities folder) and type that command.


    Alternatively, you can download a complete ISO directly from Microsoft/DigitalRiver at this link (links to ISO's are about halfway down the page).

    Choose the ISO for the version that you already have.

    Mods, this is not a link to pirated software. There are no serial numbers or activation cracks here. It points to a legitimate download source on the Microsoft Answers message boards. I am simply posting it as a reference for someone in need of help. Please do not delete this post. Thanks!
  3. BlueIS3 thread starter macrumors newbie

    Sep 5, 2011
    Thanks. I'll give that a try when I get home.

    You would think they would include some iso instructions. I even read an online tutorial that said to change the extension. And my Finder managed to read the files so I figured it had worked.
  4. BlueIS3 thread starter macrumors newbie

    Sep 5, 2011
    The Terminal method above created a file with a .cdr extension.

    I checked the -help on the command you gave and "UDTO" is not listed as one of the formats available.
  5. jdechko macrumors 68040

    Jul 1, 2004
    Apparently, the OS X hints site was incomplete. According to this site you then need to run the following command in terminal.

    mv imagefile.iso.cdr imagefile.iso
    Sorry for the incomplete help. Hope this works for you. :)
  6. BlueIS3 thread starter macrumors newbie

    Sep 5, 2011
    That did work. Thanks! File changed to an iso. Wonder why Disk Utility doesn't create iso's as a normal option.

    Incidentally, the method I actually got to work was the downloaded iso from Microsoft. There may have been issues with the rip I performed in the first place.

    My second issue was that a 4 gig flash drive was too small for boot camp assistant to use with Windows 7 Home Premium 64 bit. Wound up using a whole external drive.
  7. jdechko macrumors 68040

    Jul 1, 2004
    If you have a windows machine handy (or once you get bootcamp up and running), check out the Windows 7 USB/DVD Download tool.

    The issue is that the Bootcamp assistant wants to put both the Windows installer and the drivers on the same flash drive. This probably requires an 8GB drive, since the above mentioned tool will happily copy the Windows installer over to a 4GB drive. (I've put W7Pro 64-bit onto a 4GB drive just fine).

    You know, that or just get a bigger flash drive (8GB Sandisk for $8 from Amazon).

    That should free up your external drive while giving you a backup.

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