Is WinToUsb appropriate to build Windows 10 on external drive before installing in PC

[admin]

Directly connecting a Windows installation disk created by WinToUSB as an internal disk is not guaranteed to start properly. You have to convert it to a local installation before connecting as an internal diskplease refer to the link below:
https://www.easyuefi.com/wintousb/faq/en...-Disk.html

If you want to convert an internal disk to portable Windows, you have to do the following:
https://www.easyuefi.com/wintousb/faq/en...To-Go.html

Thank you for clarifying,

In that case, I will install the new HDD in the laptop and install OS and programs and convert the OLd HDD to be my Windows on the Go.  Not that My new OS is Windows 10 Pro but my old disk has Windows Home edition.  Both are used for Home.  Will both the Version of Windows be handled properly by WinToUSB free?

In summary, I'll only need to convert Windows Home with WInToUSB free installed on Windows 10 Pro on the same home laptop.

Before converting the old internal SSD drive to a Windows toGo drive as was last suggested, two  more questions:
1) will WindowstoUsb need to be installed on every host PC before connecting and booting into the converted drive in the futur?  (i.e. is the conversion a one time process applied to the internal drive to be converted)
2)  Will be this process be fully reversible (withWindowstoGo) if I wish to re-install back internally?

Note that in the short term I'll be using this old hard drive on the same host PC as I'll be doing and finalizing migration on a pinch.  I am thinking ahead with 1).  2) Is a concern if the conversion fails.  I did try WintoUSB but I might have forgotten to run as administrator when creating a fresh install... I couldn't upgrade the new install... which is why I started with a  more typical fresh install. 

Thank you for clarifying these points.
 Donat

The conversion is a one time process, so you don't need to install and run WinToUSB on every host PC before connecting and booting into the converted drive, and this process is fully reversible.

You said 'I couldn't upgrade the new install... which is why I started with a  more typical fresh install.' What does this mean?

The first time, after using diskpart to prep the new disk's partitions (sys, boot, ...) and using Windows 10 Pro iso, it didn't restart well (blue install screen with no progress).  When I tried a second time, it worked but then I found out no upgrade/update could be applied after the initial Windows 10 Pro install.  From your previous comments, I realized then it was simpler to start with a direct fresh install of the 'new' drive inside the PC rather in an external USB enclosure.  The benefit of using WindowstoUSB for me is to be able to boot to the 'old' drive for those odd applications I won't port and/or for the final touch of what else (data, program settings/configs) I'd like to port.  Remember that I was running out of space and setup a 2TB, so I moved ahead out of necessity and with the comfort that my old drive (Windows 10 Home, formerly upgraded from OEM Windows 8.1 home) is still operational thanks to WintoUsb.  WindowstoUSB is a new approach and it is quite handy.  Learn its usage is all.

Thank you again for your help clarifying. 

This is normal, upgrading Windows when it is booted from a USB drive is not supported, this is a limitation of Microsoft. You can find more information here:

https://docs.microsoft.com/en-us/windows...o-overview

Our product Windows To Go Upgrader can help upgrade your Windows To Go drive, for more information, please refer to:
http://www.easyuefi.com/windows-to-go-up...index.html