Run Windows 10 from an external SSD disk? Yes, it works!

Ok thanks. How would you go about installing it using EFI? In Rufus I selected to install with MBR and bios or uefi. But not sure if this does the job since its not working.

You will need a GPT format on disk, and an EFI boot disk.

Are the WiFi drivers on the external disk specific to the Mac to which the disk is connected?

You can't have both partitions active, did you mean then, one active and both "primary", meaning none of them are "logical"? And in this case which part must be active, the one in fat32 on the ntfs one?

I have a 2017 MB Pro. I downloaded the apps, partitioned and formatted the USB drive. I selected the small FAT32 partition for the install by WinToUSB and the NTFS for the boot, seemed like the only choices. How and where do I add the Apple-specific drivers? You alluded to more comprehensive instructions for accomplish this installation, but I am unable to find the reference. --DKH

I've posted this before but in less detail: This for Mac folks not familiar with using Windows commands (or would rather not). This is all done on the Mac until you actually boot into your new Windows USB.

For anyone with Parallels or VMWare Fusion it is extremely simple too. Get two free apps for Windows (I used the Mac to get them and download, to avoid crapware and then transferred the .exe once unzipped on the Mac to the Parallels.) The two apps are WintoGo (free) which uses an ISO of Windows 10 (or 8.1) to transfer to your USB3 attached external. I use an SSD and a $10 cable from Amazon. The other app you need to set up the drive without needing any knowledge what-so -ever about Bios etc. is called MiniTools Partition (free version) which allows you from Parallels to set the USB disk to MRB (essential) then partition the drive for the WintoUSB installation. Mac users are not familiar with all this stuff but two are required and it is like using Mac's own Disk Utils. You make two partitions, one small one, I use 200 MB (note that's MB not GB) and format as Fat32. Then the rest as NTSF. You then set the Fat32 partition as Primary and active then the NTFS one as active too. It all sounds complicated but it isn't really. All the options are simply there in the menus. The big difference with MiniTools Partition compared to Apple Disk Untilitiesis that it gets a little 'getting used to' in that every time to select an action, such as partition the 200 MB area, until you click the 'Apply' button nothing happens. If you do a few selections then click 'Apply' it does them sequentially. I prefer to apply each one as I go as sometimes options are not available unless the previous one is applied, e.g. you can't make a partition primary until it is formatted and so on.

I have several SSDs made this way and find a paid for utility on the Mac worth the $20, NTFS for Mac. This allows tou to mount multiple Windows bootable disks on the Mac desk top and have full read and write access. This means you can copy programs and data between then using the Finder on the Mac and not have to deal with Windows. I copy my entire Steam folder over for example. This saves hours of re-downloading.

Lastly AMD in May 2016 released Crimson Drivers for Macs running Windows. On my new Mac Pro I get full double GPU performance with AMD Catalyst now.

http://support.amd.com/en-us/download/desktop/bootcamp

Install this before anything else.

BTW I add a tild ~ in front of the AMD drivers folder in Bootcamp drivers (to prevent them even trying) if I install them later, as well as the Realtech driver folder. they both suck at time of writing. Windows installs better drivers itself. The only Apple drivers I use are the ones for the Apple keyboard. I bought a three button mouse too.

After performing your 13 steps would a clone from internal bootcamp partition work? with lets say winclone, or is this something you havent tried or know the answer to. Thanks

It may sound like 13 steps is a pain but I can do the entire process in under ten minutes and be up and running. Yes I tried WinClone, it took hours and the copy of Boot Camp failed not to mention it took a while to create the Boot Camp and partitioning my internal for Windows is not something I like doing. I have never had a failure once using WintoUSB from Parallels and it is incredibly fast using external SSDs over USB3. I just made a new one yesterday as it happens as Windows itself started acting up by refusing an update as "I wasn't using an officially sanctioned USB drive". So I simply started over from scratch from my genuine Windows 10 ISO and ten minutes later had a fully working updated Windows 10 (I'd love to know why after six months Microsoft suddenly decided to check if it was an official USB drive and then why it doesn't on installation). I stress all my external installations are digitally certified as Genuine every time as I always use the same Mac Pro I paid for and registered with Microsoft.

Using Paragon's NTFS extension on my Mac I can mount two Windows active boot drives together and use the Mac's Finder to copy folders over from one to the other. In my case it's the Steam Folders. That doesn't take long either given I have a ton of games including GTA V. Re downloading from Steam would take ages. I just reinstall Steam again so it is verified and the first time you run GTA V it installes DirectX etc.

I suspect the only area non Windows aware folks will have issues is using Mini Tools to prepare a disk. Not that it is hard but you have to know how to create two partitions (I format first in Mac using Utilities then wipe in Minitools from parallels and recreate the two partitions) and know to make them both Primary and the smaller EFI one Active. Once you learn how to do this it is easy and takes two minutes.

"A running computer with OS X to download the BootCamp software"

Not needed, Bootcamp is part of OS X, no download required,

Seems like a lot of work just to get the dubious honor of running windows. Simpler just to buy one, and doesn't pollute your Mac.

Is this h/w dependent? I have a MacBook Air. The procedure goes OK, but when I try to boot the external SSD I get a white-on-black text screen telling me that my boot configuration file is missing or damaged. I've tried many of the "how-to" procedures out there unsuccessfully. Many posts say "you can't boot Windows 10 off an external drive" but then I see posts where plenty of folks have.

Nope not hardware specific (within reason), I can boot to an external SSD from any of my Macs. The problem is most likely you did in incorrectly. It's mind blowingly easy once you know (like most things.) But tricky first few times.

OK How to with screen shots:

This all assumes you are running Parallels or VMWare with an SSD already formatted on the Mac as ExFat as a single volume. You dismount the SSD in the Mac Finder and re attach with Parallels running (Windows 10) and select parallels for the SSD to mount in.

The trick is setting up the SSD using a free utility on the Parallels side (i.e. it's a Windows app) called miniTools Partition Free: https://www.partitionwizard.com/free-partition-manager.html

I downloaded on the Mac then dragged to Parallels. Then learn how to use this very clever utility.

You delete the SSD, then Create a new 200 MB partition as Fat32, set to Primary (Not Logical) and Active. Once done create another partition set to NTFS and Primary using all the remaining space. Sounds easy but takes a while to fathom out the interface I know. Once you do it's as easy as Disk Utilities.

Now you can move to the next step. You need a genuine Windows 10 ISO (The Anniversary version is available at Microsoft) https://www.microsoft.com/en-us/software-download/windows10ISOAgain I download the ISO on Mac and drag to Parallels desktop. I bought on Amazon and this gave me a digital registration tied to my Mac on which I did the first installation. Great thing is as many SSDs I make they all automatically get activated as genuine. Do not try to get around this, Microsoft are good and screwing with the installation after a very short time of you don't have a legit activation code.

Next obtain WintoUSB free version. https://www.microsoft.com/en-us/software-download/windows10ISO Again I download on Mac and drag to Parallels Desktop

Run WintoUSB, select the ISO and then the destination disk, you will see this if you correctly set up the SSD in miniTools Partition:

Check the EFI (FAT32 small partition) as the system partition then the larger NTFS as the boot partition as shown above. Don't forget the extra step of making the small partition 'Active in miniTools Partition.

Click Next and in my case over USB3 and a 256 GB SSD it takes about ten minutes to complete. Shut down Mac and reboot with option held and select EFI and start the procedures as per normal (several restarts).

I have Paragon's NTFS extension on my Mac.

https://www.paragon-software.com/home/ntfs-mac/

This is so I can, once Windows is finally installed, I quit it and reboot to the Mac. The Paragon extension allows me to drag anything I want into my Windows SSD (I use user/myname/downloads) just as a protocol I've adopted for things like zip extractors and BootCamp Drivers.

I also can mount earlier made Windows SSDs in the Finder and drag entire installations such as Steam folder out of Program Files (86) etc. from one SSD to the other (to the same place obviously) and happily work away on my Mac as this is being done, no need to do anything in Windows.

This is the installed Windows 10 volume seen in the Mac's Finder.

It all seems tricky but once you master MiniTools Partition is is a walk in the park. I can do all of the above in half an hour including copying over my Steam and user data from a previous set up SSD.

Digitalclips wrote:

It all seems tricky but once you master MiniTools Partition is is a walk in the park.

You can also do the same thing using the built-in Diskpart executable on the W10 ISO. 😉

Agreed but IMHO not as Mac like and intuitive for non PC users.

Caveat ... The actual creation of an external bootable Windows SSD is tied to the machine that made it and to which the Windows license is applied. It may boot to another Mac you own but it won't be seen as licensed.