Bootcamp Windows 10 from External Drive?

[TPadden]

Trying to move a Bootcamp partition to a bootable external drive. .......

Sorry, we are talking about very different things and I can't help you with that. From the beginning I thought I was VERY clear that I was talking about INSTALLING then running Windows from an external drive, that is bootable on a Mac.

The OP's question also stated that:

hello,

I am wondering whether it is possible to install and boot windows 10 preview from an external hard drive?

I don't think I can help you in your efforts other than to recommend you take a look at Winclone ...... but I don't think it will do what you want either.

Again, sorry about any confusion ..... I'm pretty sure in the past I've done what you want but I just don't remember how. I may have mounted the external drive internally then removed it - I also have a Mac Pro which I change drives on like my underware (with an "option" boot I sometimes have a choice of 4 or 5 bootable drives) ......

 

[steve62388]

Sorry, we are talking about very different things and I can't help you with that. From the beginning I thought I was VERY clear that I was talking about INSTALLING then running Windows from an external drive, that is bootable on a Mac.

Yeah, that's fine. I can do a clean install.

 

[NazgulRR]

OK, just took an external USB3 250GB SSD, formatted it NTFS 4K Sectors, ran WintoUSB ...... selected Win 10 ISO build 9879, selected the SSD drive, it went right to the select boot and sysetms partitions (I selected the same partition), it went right to installing...... 4 minutes later I copied Bootcamp 5.1.5621 to the drive. I then plugged it into my Mac Mini and booted right into Win 10, I then ran the Bootcamp setup for drivers and was done..

I just did that same thing with Windows 8.1, except that I let WinToUSB handle the formatting.

Plugging the finished drive into my MBA under OSX results in "The disk you inserted was not readable by this computer" message.

If I reboot it and hold down the option key, I do get the option to boot into Windows. However, booting into Windows results in a black screen with an underscore flashing in top left corner that doesn't go away. Is it supposed to be that way and is something that I should just wait out?

I don't have access to a Windows machine for another two days so I can't really repeat the WinToUSB installation.

 

[TPadden]

I just did that same thing with Windows 8.1, except that I let WinToUSB handle the formatting.

Plugging the finished drive into my MBA under OSX results in "The disk you inserted was not readable by this computer" message.

If I reboot it and hold down the option key, I do get the option to boot into Windows. However, booting into Windows results in a black screen with an underscore flashing in top left corner that doesn't go away. Is it supposed to be that way and is something that I should just wait out?

I don't have access to a Windows machine for another two days so I can't really repeat the WinToUSB installation.

Waiting probably won't do any good; it should almost immediately go to the spinning dot Setting Up Devices screen. Probably due to GPT vs MBR partition Map Scheme/ Table, I've had more luck setting external drives up with MBR. The Disk initialization (MBR vs GPT) is done before partitioning. A GPT scheme will only boot on UEFI based computers.

 

[NazgulRR]

Waiting probably won't do any good; it should almost immediately go to the spinning dot Setting Up Devices screen. Probably due to GPT vs MBR partition Map Scheme/ Table, I've had more luck setting external drives up with MBR. The Disk initialization (MBR vs GPT) is done before partitioning. A GPT scheme will only boot on UEFI based computers.

It is MBR. Are you suggesting that I should format it GPT? The computer in question is a 2013 MBA.

 

[TPadden]

It is MBR. Are you suggesting that I should format it GPT? The computer in question is a 2013 MBA.

Nope, MBR should be good. I have used my drives (Win 10 and 8.1) on both my 2013 MBA and my wife's 2012 MBA as well as both of our Mini's. Not sure what happened to your set up. I'd try a couple of "option' boots, giving it time to work through (it can spend some time setting up devices, booting a couple times), and if it doesn't work set it up again from square one.

 

[NazgulRR]

Nope, MBR should be good. I have used my drives (Win 10 and 8.1) on both my 2013 MBA and my wife's 2012 MBA as well as both of our Mini's. Not sure what happened to your set up. I'd try a couple of "option' boots, giving it time to work through (it can spend some time setting up devices, booting a couple times), and if it doesn't work set it up again from square one.

I just got a trial version of Parallels so I can work on it on my MBA.

1) Is there a way to run the installation process with WinToBoot without it formatting the drive? It always formats the drive...

2) Do your Win 10 and 8.1 mount under OSX as NTFS drives?

 

[TPadden]

I just got a trial version of Parallels so I can work on it on my MBA.

1) Is there a way to run the installation process with WinToBoot without it formatting the drive? It always formats the drive...

2) Do your Win 10 and 8.1 mount under OSX as NTFS drives?

I don't use Wintoboot or a VM.

My external WintoUSB drives are NTFS formatted that mount at boot outside of OSX.

 

[NazgulRR]

I don't use Wintoboot or a VM.

My external WintoUSB drives are NTFS formatted that mount at boot outside of OSX.

Sorry, I meant WinToUSB of course.

Say you wanted to plug one of your WinToUSB drives under OSX, would it mount as any other NTFS drive? This is what I get (on all of my three reinstalls so far):

Just trying to see if something went wrong there already...

 

[TPadden]

Just trying to see if something went wrong there already...

I'd guess so; within OSX (Yosemite) the drive mounts fine as a NFTS drive ......

 

[NazgulRR]

I'd guess so; within OSX (Yosemite) the drive mounts fine as a NFTS drive ......

I just re-did the installation for the 4th time, this time using GPT partition table.

As soon as it was done, the drive mounted on the OSX desktop just as on your screenshot .

Windows 8.1 also booted up when restarting the MBA and holding down the option key (this time the drive showed up as "EFI" as opposed to "Windows"), however, it didn't get past the logo and the spinning icon after as long as 10minutes .

I am now re-doing the installation for the 5th time, this time using a different 8.1 ISO (although the previous .ISO should have worked as well if it was good enough for Parallels installation?).

One more question - are you sure that you that WinToUSB can install Windows onto a USB drive without formatting it? It always formats it for me and there doesn't seem to be a way to skip that...

 

[TPadden]

I just re-did the installation for the 4th time, this time using GPT partition table. .....
Windows 8.1 also booted up when restarting the MBA and holding down the option key (this time the drive showed up as "EFI" as opposed to "Windows"), however, it didn't get past the logo and the spinning icon after as long as 10minutes ........
One more question - are you sure that you that WinToUSB can install Windows onto a USB drive without formatting it? It always formats it for me and there doesn't seem to be a way to skip that...

Nope, not positive, I'd have to do it again to be absolutely sure. It seems to me that the screen I get after selecting the ISO is a screen where I select the already formatted target System and Boot partition. I don't remember any re-formatting ...... connect the drive directly to a USB port, not through a hub ....

Either way, I've used multiple drives and multiple ISO's without a problem. Sounds like you might be running into a driver problem. Disconnect everything you can from the install computer before running WintoUSB .......

 

[NazgulRR]

Either way, I've used multiple drives and multiple ISO's without a problem. Sounds like you might be running into a driver problem. Disconnect everything you can from the install computer before running WintoUSB .......

Out of curiosity, do the drives that you have set up with 8.1 and 10 appear as 'removable drives' or 'local drives' in windows environment?

 

[TPadden]

Out of curiosity, do the drives that you have set up with 8.1 and 10 appear as 'removable drives' or 'local drives' in windows environment?

Local drives in Windows File Explorer; in Device Manager: Disk Drives/SCSI Disk Device.

 

[NazgulRR]

Local drives in Windows File Explorer; in Device Manager: Disk Drives/SCSI Disk Device.

This might be a problem - mine reports as a removable device (as it is a USB 3.0 thumb drive). Is there a way to reconfigure a drive?

According to this tutorial: http://www.rmprepusb.com/tutorials/win8togo Win 8.1. will not boot from removable devices, but Win 8 will.

I'm going to try Win 10 next (first GPT, then MBR), followed by Win 8 (again, first GPT, then MBR). Will report back later.

 

[TPadden]

This might be a problem - mine reports as a removable device (as it is a USB 3.0 thumb drive). Is there a way to reconfigure a drive?

According to this tutorial: http://www.rmprepusb.com/tutorials/win8togo Win 8.1. will not boot from removable devices, but Win 8 will.

I'm going to try Win 10 next (first GPT, then MBR), followed by Win 8 (again, first GPT, then MBR). Will report back later.

Frankly, I liked Windows 10 so much I just installed it on my mini internal SSD. I'll just leave OSX as my MBA system with another SSD external for the occasion I need Windows on the go.

 

[bmac89]

I've never had a problem booting from external drives, USB and Firewire, using either Windows 8.1 or 10 Technical Preview.

I have bought a new external drive - formatted it as NTFS MBR in Windows. WinToUSB would not let me install to GPT so I had to use MBR.

I then used WinToUSB to install Windows 10 Tech Preview. It succesfully installed and boots from a Windows PC. However as i suspected might happen, it won't boot from my Mac. I have installed rEFIt and it recognises the Windows 10 Partition, however when I select it, it still boots into the internal bootcamp partition running Windows XP rather than Win 10 on the external drive.

Any help or suggestions appreciated?

An idea of the top of my head - If I clone the Windows 10 drive and restore it to a Mac OS Journaled GPT external drive is it likely to boot? (I am guessing not!) If so can you suggest a free windows based program which will allow me to create a bootable clone?

Many thanks for your help.

P.S. I got it working... see post below.

 

[bmac89]

I have bought a new external drive - formatted it as NTFS MBR in Windows. WinToUSB would not let me install to GPT so I had to use MBR.

I then used WinToUSB to install Windows 10 Tech Preview. It succesfully installed and boots from a Windows PC. However as i suspected might happen, it won't boot from my Mac. I have installed rEFIt and it recognises the Windows 10 Partition, however when I select it, it still boots into the internal bootcamp partition running Windows XP rather than Win 10 on the external drive.

Any help or suggestions appreciated?

An idea of the top of my head - If I clone the Windows 10 drive and restore it to a Mac OS Journaled GPT external drive is it likely to boot? (I am guessing not!) If so can you suggest a free windows based program which will allow me to create a bootable clone?

Many thanks for your help.

I got it working, but unfortunately I had to delete my Bootcamp partition for it to boot. I used rEFIt to boot.

Thanks for your help.

 

[NazgulRR]

I got it working now too.

Local drives in Windows File Explorer; in Device Manager: Disk Drives/SCSI Disk Device.

This was the trick. Windows 8.1 (and presumably 10 too, but not 8) will boot off an external drive only if it is recognised as a local fixed drive (as opposed to a removable type drive). Alas, most usb thumb drives are of the removable type.

I managed to re-flash the firmware of my Transcend JetFlash 760 USB3.0 32GB drive so it is now recognised as a local drive in Windows, which, after following through with the WinToUSB installation of Windows 8.1 (interestingly enough, this time WinToUSB did not re-format the drive or ask me to choose between GPT/MBR tables), now allows me to run a full install of Windows 8.1 from it.

 

[EdDuPlessis]

For manual installing Windows you have to 'bless' the Windows partition if you want it to boot but I have no idea how to do this blessing. Bootcamp does it as part of the install.

 

[TPadden]

....Bootcamp does it as part of the install.

I do not use Bootcamp for any part of the install. I just use the Bootcamp drivers AFTER I have an operating external Windows drive.

 

[EdDuPlessis]

I do not use Bootcamp for any part of the install. I just use the Bootcamp drivers AFTER I have an operating external Windows drive.

How do you bless the drive so that the Mac accepts it as a bootable volume?

 

[TPadden]

How do you bless the drive so that the Mac accepts it as a bootable volume?

I have no idea what you are asking, but I don't use Holy Water or sacrifice a chicken! The drive is select-able in a non-denominational "Option" boot.

 

[EdDuPlessis]

I have no idea what you are asking, but I don't use Holy Water or sacrifice a chicken! The drive is select-able in a non-denominational "Option" boot.

I tried just to "Option" boot a vanilla Windows install on external drive and it didn't work. When I tried Start Up disk my Mac tells me the drive isn't blessed. I was about to get a priest or something to do it, but this forum might help better

 

[TPadden]

I tried just to "Option" boot a vanilla Windows install on external drive and it didn't work. When I tried Start Up disk my Mac tells me the drive isn't blessed. I was about to get a priest or something to do it, but this forum might help better

By vanilla do you mean either WintoUSB or WintoGo? Vanilla Windows won't boot from a USB connected drive other than to install ... I also notice free AOMEI Partition Assistant offers a "Windows to Go Creater" om it's menu, but I haven't used it to make an external Windows drive ......