Bootcamp on external SSD?

Discussion in 'Windows, Linux & Others on the Mac' started by bubulol, Apr 3, 2015.

  1. bubulol macrumors 6502a

    Mar 7, 2013
    hey, due to my thigh amount of GB available on my MBA (128), i want to install win7 through bootcamp
    Does it worth it to install it via external SSD?
    I find one, pretty small (like only twice bigger than an USB key, unbelievable but true lol), according specs, fast enough (up to 400 m/s)...
    250 GB for 170 bucks around
    USB 3.0 ,UAP mode included

    What the best way to install Win?

    Bootcamp and split internal SSD in half, both OS would be about equal size
    or installing win 7 on external SSD?

    Thanks in advance
  2. yjchua95, Apr 3, 2015
    Last edited: May 23, 2015

    yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    Connect external drive to Windows VM. You must have a Windows VM in VMware/Parallels/VBox, or a Windows PC. Any existing Windows environment will do.

    Note: If you’re using a 32-bit ISO, your Windows environment used to do these commands have to be 32-bit. And if it’s a 64-bit ISO, the environment has to be 64-bit.

    What you need:
    install.wim file (obtain this from your Windows ISO)

    Open elevated cmd.exe (run as admin)

    Note: All commands aren't case sensitive, including pathway to files.

    Type diskpart
    Type list disk
    Take note of the disk you want to select
    Type select disk 1 (if your disk is Disk 1)
    Type clean
    Type convert gpt (do this and then stop at this point if you're using a drive with a Thunderbolt port. If installing in BIOS-CSM, type convert mbr and then stop at this point if you’re using a drive with a Thunderbolt port)
    Type create partition EFI size=100 (skip if installing in BIOS-CSM)
    Type format quick fs=fat32 label=EFI (skip if installing in BIOS-CSM)
    Type assign letter=S (skip if installing in BIOS-CSM)
    Type create partition primary
    Type format fs=ntfs quick label=W2G (or any other name you wish for label)
    Type assign letter=E
    Type exit

    Open up File Explorer. In your C drive, create a new folder named WIN2GO.
    Put the install.wim file in this folder

    Back in cmd.exe:
    Type dism /apply-image /imagefile:C:\WIN2GO\install.wim /index:1 /applydir:E:\ (this process will take quite a while)
    Type E:\Windows\System32\bcdboot E:\Windows /s S: /f UEFI (use this one for UEFI installation)
    Type E:\Windows\System32\bcdboot E:\Windows /s E: /f ALL (use this one for BIOS-CSM installation)

    Restart your entire Mac. After the chime, hold down Option and when prompted to select your boot drive, select EFI Boot (or whatever else that comes up for a BIOS-CSM installation).

    Proceed installation normally.

    After installation, install Boot Camp drivers. Feel free to trash the VM once you're done too.

    For best results, use USB 3/Thunderbolt. If you don't have USB 3, use Thunderbolt. If you have neither, stick back to the internal drive :)

    Don’t use a USB stick.

    Note: This method involves reformatting the entire external drive.

    For Thunderbolt drives, just boot from the Windows USB installer and install directly onto the TB drive. Windows sees TB drives as an internal PCIe connection. However, you must format the TB drive as GPT first.

    CAUTION: Windows can only be installed in UEFI flawlessly on Haswell Macs and later. Ivy Bridge and earlier Macs can only run Windows in BIOS-CSM flawlessly. Attempts to boot a UEFI installation of Windows on an Ivy Bridge or earlier Mac will result in driver issues.

    These steps do not work with Windows 7, as it lacks the dism.exe utility.

    UEFI-compatible Macs:
    MacBook Air (mid-2013 and later)
    iMac (late-2013 and later)
    Retina MacBook Pro (late-2013 and later)
    Mac Pro (trashcan shape)
    Mac Mini (late-2014 and later)

    Long story short, only Macs with PCIe SSDs support UEFI. Non-retina MBPs, along with other Macs not listed above (basically all Ivy Bridge and older Macs), are not UEFI compatible.

    WinToUSB basically does the same thing, but doesn’t always work because WinToUSB doesn’t really take into account between BIOS-CSM and UEFI Macs; it only uses one method for all (which may result in boot failures and other problems).

    I run Windows off a single Transcend 960GB JetDrive and constantly use it between Macs without problems.

    Edited with instructions for both UEFI and BIOS-CSM Macs.
  3. bubulol thread starter macrumors 6502a

    Mar 7, 2013
    thx for your sharing
    i found this in order to install win through external hard drive


    I don't know if it exists other brands but it one of smallest external SSD i ever seen :eek:
  4. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    I use a small-sized Transcend 960GB JetDrive.

    You can also use an Angelbird SSD2Go (which is really aesthetically well-designed) or the Samsung T1 (uses an 850 Evo inside it and is really light).
  5. bubulol thread starter macrumors 6502a

    Mar 7, 2013
    Nice but too expensive for me :(
    One question about bootcamp on external hard drive
    i ve heard it would be quite difficult to hit alt manip before launching win instead of OSX, because of timing, is that true?
  6. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    Nope, it's absolutely false.

    Immediately upon the chime, I just hold the Alt key, type my EFI password (EFI lock has to be manually enabled through Recovery options), then select the boot drive.
  7. bubulol thread starter macrumors 6502a

    Mar 7, 2013
    i m struggling with cmd.exe and fs=format quick
    Neither fat32 nor ntfs works :(
    I don't have standard SSD but mSata, could it be the guilty?
  8. yjchua95 macrumors 604

    Apr 23, 2011
    GVA, KUL, MEL (current), ZQN
    Shouldn't be. My 960GB Transcend JetDrive is also an mSATA SSD connected in a UASP USB 3 enclosure, and it works fine.
  9. bubulol thread starter macrumors 6502a

    Mar 7, 2013
    Actually Diskpart through cmd.exe doesnt seem to work at all
    I need to figure it out why the hells i cant, my partition manager software does work :confused:

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