How to run Boot Camp on External Hard Drive?

This is not helpful nor does it actually answer the OP's question, as this assumes you already have Windows installed. The point of this thread is to install Windows on an external drive through Boot Camp, not copy an existing Boot Camp partition (which is fairly simple to do). The answer is already further up the thread: installing to an external drive is only possible over Thunderbolt. This makes sense because TB is simply an extension of the PCIe interface.

Forget it, didn't see who you answered at först.

✌️ I'm glad that my guide worked for some of you. If it didn't, it's because you surely didn't follow it thoroughly.

@GGooeytoe

Maybe you should use the .iso instead of the USB drive made from the .iso. That does not change anything, you're right, but you never know, maybe it does. Anyway, maybe you should try to start over.

@AirGoggles

You can't install windows 8.1 to a USB drive, whether there is a Mac involved OR EVEN A REAL PC. You just can't! The Windows 8 installer prevents this kind of installation (not sure about previous Windows, but I'm pretty sure that's the same).

You're sure that Windows 8.1 installer considers a Thunderbolt drive as an Internal drive like a SATA drive ?

I don't own a Thunderbolt drive. nor does 95 % of the regular Mac users.

Nowhere did I say anything about Windows 8 so why are you asking me? From the experience that others here have pointed out, it works.

The issue with the Thunderbolt drive isn't a Windows issue; it's a Boot Camp issue. Boot Camp simply doesn't give you the option to install Windows on an external drive. Thunderbolt drives seem to be the exception, likely because they are an external extension of the PCIe interface (an internal connection). I've installed Windows XP on a USB hard drive through Boot Camp before, so this is a change within the last couple years.

I haven't tried that and it might make the difference, but I found an "easier" way:

Use a free tool called Win2Go. I think it probably does exactly what you described, but it does it for you. Guide follows.

What you need: a .iso or .img of windows 8.1 (should work with other versions, but this guide won't be quite right)

a windows install usb stick you created with boot camp (make sure you had the second option, "Download drivers," checked. The drivers are what we care about.)

A windows machine with administrator privileges and (preferably) USB 3.0 ports

a Macintosh computer (duh! :D)

1. Get a .iso of Windows 8.1 (it can also do earlier versions, but this is the one I know). If you have a .img like I did, simply rename it as a .iso. DO NOT have your bootcamp usb stick plugged in during this entire process. It gets very confused and tries to install windows to your internal drive around step 10 if you do.
2. Partition the drive you intend to install windows on. I did this using MacOS's Disk Utility because I knew how. Anyway, make at least one partition on the drive named "WINDOWS" with at least 20 GB of space (could use less, but if you want to be able to do anything later, more is better.) The format of the partition is unimportant at this point.
3. Get access to a windows device as an administrator. I used a bootcamped macmini running windows 7.
4. Put the windows .iso from step 1 somewhere the windows account from step 3 can see it (i.e. on a flashdrive).
5. Download Win2USB from http://www.easyuefi.com/wintousb/ and install it. You can do steps 6 and 7 while this is occurring, but it should be pretty fast.
6. Plug the drive into your windows device, preferably via a USB 3.0 port.
7. Right click on the "WINDOWS" volume that should appear in windows explorer. Choose "format" and format the partition to MS-DOS.
8. Start up Win2USB and work through the wizard:
   1. Choose the .iso from steps 1 and 4 as your source.
   2. Make the WINDOWS partition both the system and boot partition (you could get fancy and make two, but I didn't bother).
   3. Let it run. This will take some time; try not to do anything on the computer while it is installing. I maxed out my internal drive's read/write speed during this process.
9. Once it is done, EJECT the harddrive (windows may refuse to do this; if so, simply turn the computer off before removing it).
10. Plug the drive into your mac and hold down OPTION while it starts up. You should see a screen with all of your partitions shown, plus one (or possibly two) orange things named windows. Use the arrow keys to pick either of the windows choices (they are actually the same thing as far as I can tell) and hit enter.
11. It should boot into windows and take a LOONG time, then shut down. Do step 10 again and it should boot fully, as well as asking for your product key.
12. Make sure it takes your product key and boots fully. Things may look weird and you probably won't have internet access; the next steps fix this.
13. Boot your new windows partition and then insert the bootcamp flashdrive (NOT the other way round).
14. Navigate to the folder on the flashdrive called BootCamp and run setup.exe. It will install the drivers you need to make your apple wifi chips, graphics stuff, keyboards, etc work properly. The screen will probably do strange things during this process and especially as it is finishing. Don't panic.
15. Reboot, possibly more than once. Basically, you just keep rebooting until it stops doing weird stuff. It took me two cycles.
16. Everything should work at this point. If not, I forgot something.

Anyone here tried on of the solutions given here with a OWC Mercury Elite Pro Dual TB (2-bay) enclosure? I managed to get both OSX 10.10.1 and W7 working on a DeLock 2.5" TB enclosure, but as I have only one of these, I need to swap drives. That's too much of a hassle.

Just bought the Pro Dual, but that darned box just refuses to boot W7 at all. With a standard OSX/Bootcamp W7 internal disk, if the Pro Dual is connected via TB, only OSX boots... Windows shows a black screen with blinking cursor.

Thymen

Can you post the output of diskutil list with the external TB enclosure connected?

Loner T, Sorry for the late reply, have been quite busy.

The listing:

/dev/disk0 >> internal HDD

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 798.3 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data BOOTCAMP 201.0 GB disk0s4

/dev/disk1 >> W7 SSD in DeLock TB housing

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *250.1 GB disk1

1: EFI EFI 209.7 MB disk1s1

2: Microsoft Basic Data W7SSD 224.8 GB disk1s2

/dev/disk2 >> OSX SSD in OWC Elite Dual Pro TB housing, in the bootable bay

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.1 GB disk2

1: EFI EFI 209.7 MB disk2s1

2: Apple_HFS SSD 499.2 GB disk2s2

3: Apple_Boot Recovery HD 650.0 MB disk2s3

Now, if I keep the Elite Pro switched on a boot time, neither W7 in disk 0, or disk 1, starts. I get a black screen with blinking cursor.

Switch off disk 2 (the Elite Pro), and OSX @ disk 0, W7 @ disk 0 and W7 @ disk 1 boot without a hitch.

I solved the problem, by putting the plug of the Elite Pro in a switched plug/socket housing. Switch ON for booting OSX @ disk 2, switch OFF for booting Windows @ disk 0 or 1, or OSX @ disk 0.

It is a solution, albeit not the one I had in mind.... If anyone knows how to circumvent the problem, let me know.

Oh yes, people @ OWC: you state the Elite @ TB is not compatible with BootCamp: it is the other way around: BootCamp is not compatible with the Elite @ TB. Quite a difference...

Thymen

With everything on, as a test, execute a SMC Reset and a PRAM(NVRAM) reset. There is information in the NVRAM which can cause Bootcamp to run into issues.

The black screen with a blinking underline cursor indicates that the Windows bootmanager has failed to load the bootblock. There is a tool called EasyBCD which may also prove helpful, it allows you to add more than one Windows in the boot options.

Can you post the output of the following commands?

sudo fdisk /dev/disk0

sudo fdisk /dev/disk1

I already did the SMC/PRAM reset; I used EasyBCD to change the names of the windows, and shorten the boot pause.

When I start the system with Option key pressed, I see one Windows boot option only; select that one, then the Windows boot manager kicks in and allows me to choose between either one of the windows I have installed: the Bootcamp one on the internal hdd, the other one on the TB SSD. Select StarUp disk from within OSX shows both windows installatiiions, though.

The SSD windows I have installed manually, from within the W7 Bootcamp. I used a script that custom installs windows, in order to use the GPT partition style. If you install windows by selecting the installation DVD, the target disk needs to be MBR style. Works, and with a 256 GB disk it is no problem, but I prefer the GPT style.

Howto: see http://www.intowindows.com/how-to-install-windows-7-to-usb-external-hard-drive-m ust-read/

Create a flash drive using the Bootcamp assistant to hold all the drivers, and run bootcamp.exe on it after you have installed windows. Did not try this with USB disk, but it might work...

Not sure, but for Windows 8.1, it may be possible to directly install from the dvd, without going through Bootcamp and having windows installed on the HDD. W8.1 uses EFI, so perhaps it installs the boot info on the external disk, where W7 relies on the EFI on the internal disk to get started. But I have spent enough money so far, and W7 works fine for me.

The listing:

Disk: /dev/disk0 geometry: 121601/255/63 [1953525168 sectors] >>> HDD !!!

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 1559267840] HFS+

3: AB 1023 254 63 - 1023 254 63 [1559677480 - 1269536] Darwin Boot

*4: 07 1023 254 63 - 1023 254 63 [1560948736 - 392574976] HPFS/QNX/AUX

Disk: /dev/disk1 geometry: 30401/255/63 [488397168 sectors] >>>> SSD !!!

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 1023 254 63 - 1023 254 63 [ 1 - 488397167] <Unknown ID>

2: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

3: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

The SSD installation of W7 does not seem to be EFI. It has a GPT and a Protective MBR, but since it has no MBR, Apple's Bootmanager cannot boot it. It can boot W7 on disk0 only. Bootcamp has no knowledge of any dual-boot within Windows.

When I start the system with Option key pressed, I see one Windows boot option only; select that one, then the Windows boot manager kicks in and allows me to choose between either one of the windows I have installed: the Bootcamp one on the internal hdd, the other one on the TB SSD.

This behavior is what you see as you have documented.

Select StarUp disk from within OSX shows both windows installatiiions, though.

Because there are two GPT entries and NTFS file systems (disk0s4 and disk1s2). It switches to CSM-BIOS and points to the respective Bootloader. There is nothing for it to use on the SSD, hence the blinking cursor.

Since both the OWC and the DeLock are TB devices, how are they connected? What type of Mac are you using?

Loner T;

I have a 27" iMac, mid 2011 model. Has two Thunderbolt ports. The OWC enclosure with the OSX SSD is connected directly to one port, the DeLock enclosure with the W7 SSD is daisy chained after a CallDigit TB dock. But, while testing, both were directly connected to a TB port on the iMac.

I tried multiple scenarios:

1. internal HDD with OSX only, install W7 directly from dvd on MBR/NTFS SSD; installs, but does not show at Option-boot; shows as StartUp Disk in OSX, but does not boot.
2. Internal HDD with OSX only, attempt to install directly from dvd on GPT/NTFS disk; Windows refuses to install on GPT style disk
3. Internal HDD with OSX and W7 via Bootcamp, install W7 directly from dvd on MBR/NTFS SSD; installs, shows 1 x Windows at Option-boot and allows to select either one of the W7 installations at the Windows bootmanager; external W7 shows at StartUp Disk, but boots as if via Option-boot.
4. Internal HDD with OSX and W7 via Bootcamp, install W7 directly from dvd on GPT/NTFS SSD; Windows refuses to install on GPT disk
5. Internal HDD with OSX and W7 via Bootcamp, while in W7 @ internal HDD, install W7 via script according the link in my previous post. Disk = GPT, formatted NTFS. Installs, shows 1 x Windows at Option-boot and allows to select either one of the W7 installations at the Windows bootmanager; external W7 shows as StartUp Disk in OSX, but boots as if via Option-boot.

I have set up my system now according item 5, plus a switch to turn the OWC on/off. I still wonder though why the OWC enclosure hijacks the boot process, and causes all these troubles. The DeLock enclosure does not do that. Perhaps because the OWC has daisy chaining capabilities?

If one installs OSX on an external disk, it creates an EFI system partition on that disk. I assume that all that is required to boot from that disk is in that partition. I cannot remove my internal disk, so can't test it. It seems to me that W7 relies on the boot info stored by Bootcamp on the EFI of the internal disk. Now I wonder if W8.1, since (afaik) it uses EFI bootmanagement, stores the boot info on the EFI system partition on the external disk as OSX does, and therefor can be installed/booted without having Windows installed on the internal drive. And perhaps the same for Linux?

Possible perhaps, but I do not have W8.1 available. Could have downloaded a trial ISO, but I have done enough installation trial and error for the time being...

Can I suggest this configuration?

Remove W7 SSD from DeLock and put it in the OWC EDP bootable bay (current disk1 in OWC EDP).

Disconnect the DeLock (which should now have the OSX - current disk2).

Test individually for W7 SSD and OSX and then directly connect to iMac and test again.

W8+ seems to be much better at EFI support than W7 does. W7 EFI has given me problems on Graphics and Audio.

You also have a TB (v1) iMac. You can take the two external enclosures to in the configuration of your choice to the nearest Apple Store and try your test scenarios on a 2013/2014 iMac is a 'full' UEFI Mac and has TB (v2).

Loner T;

I tried the config you propose: the W7 SSD in the OWC enclosure, does NOT boot, no matter how you install it. Also: with W7 perfectly running on the Internal disk via BootCamp, and NO disk, or and UNFORMATTED disk, or a FORMATTED disk, or a properly working OSX SSD in the OWC's bootable bay.... connect via TB and booting the internal W7 yields the black screen/blinking cursor.

When the OWC arrived, I had the OSX SSD in the DeLock enclosure, but I already had the W7 SSD prepared and tested in the DeLock as well. Ran perfectly either way. First thing I did was to put the W7 SSD in the OWC: no go! black screen/blinking cursor. I subsequently tried all possible combinations. Must have re-installed W7 perhaps 6 times or so, in various way. Result were alway the same.

As I mentioned before, the Elite Pro Dual @ TB is not not-Bootcamp compatible, but the other way around: Bootcamp is not Elite Pro @ TB compatible. At least, in MY set-up.

As soon as I have some new energy, and curiosity is getting the better of me, I'll try to get a trial W8.1 disk or flash drive, and see if I can get that combo working. But NOT during Christmas, that's for sure!

I do not have an OWC EDP to test with, but I will try to get one. It may take me a couple of weeks though. I am curious, too.

If DeLock TB works with BC, but OWC EDP does not, I suspect that OWC is not being candid about how they have implemented it.