default wrote:
On Tue, 10 Jul 2018 23:20:42 +0200, "Carlos E.R."
wrote:

Hi,

I bought a Lenovo Yoga 300-11IBR. It came with an internal 500GB
rotating rust hard disk. I played with it a few days, let its 2 year
Windows 10 update itself, then removed the hard disk, installed an SSD
instead (smaller), on which I installed another operating system.

I placed the original hard disk (that has the original W10 inside) in an
external USB3 enclosure and tried to boot it. It does start to boot,
then suddenly aborts and boots the internal disk instead (with another OS).

Is there something that can be done to boot Windows from the external drive?

I found info on how to install Windows 10 on an external drive, but that
is not my exact case:

https://www.pcworld.com/article/3185777/windows/how-to-install-windows-on-an-external-drive.html
How to install Windows on an external drive

https://www.easyuefi.com/wintousb/
Best Free Windows To Go Creator to create portable Windows 10/8.1/8/7!

I've done that with earlier versions of Windows, but using an ESATA
drive not a USB drive.

But does the BIOS allow you to change the boot order to the USB
instead of the HDD? I'd try that first.... No experience with the
Yoga so I can't say what you can or cannot do in BIOS.

But that's an entirely different situation.

Booting ESATA externally is no harder to do than booting
SATA internally. You need a driver of course (and the ESATA
could be coming from a second chip), but other than
that, it should be easy to do. It should remain fine,
as long as the license and activation are for one machine,
not dragging the ESATA drive around and plugging it into
20 different machines.

The USB boot option requires help. In the old days that
was BootBusExtender. Today it's Windows To Go, for no
particular reason. It's just a Windows configuration
that supposed to support booting over USB. With an
Enterprise SKU, it's supposed to also take into account
the licensing and activation.

I also see reference in the articles above, to "booting VHD".
I tried that here (not as a part of the above referenced product),
and it got into a loop and wouldn't settle down. That
didn't involve USB at all, and was just a VHD staged
on internal storage. But it didn't work for me. And by
looping, that makes it pretty hard to debug. No nice
neat "crash" with an error number to use for guidance.

Paul