“Windows To Go” is a portable windows environment that Microsoft developed. While Microsoft says they are no longer developing this, it is still available for use on recent versions of windows 10. For the Microsoft overview see: https://docs.microsoft.com/en-us/windows/deployment/planning/windows-to-go-overview
I have used this to specifically create “portable” windows environments that boot most hardware from an external SSD drive. I say portable meaning that with “windows to go”, the windows OS installed on the external drive drops back into a setup mode when it detects that it is being booted on different hardware. This setup mode at boot time then tries to bring in the needed hardware drivers auto-magically for the new hardware this disk is being booted on. This is largely successful on most hardware as long as the network driver is sufficient to get a network connection. I have booted the very same Windows to Go disk without having to install anything new on Dell precisions, Dell optiplexes, Apple iMacs, Apple mac minis, Apple Mac Pros, etc.
While there is a built in process to create a “Windows to Go” disk in Windows 10 (type “Windows to Go” in the start menu search box), I have most recently been using the free utility Rufus to build these disks directly from our institutional windows ISO. Rufus can be found at: https://rufus.ie/ and below is a screen shot of the settings I have been using.
You will also need a copy of the Windows ISO for your institution, and, if applicable, your windows activation key. (We use KMS servers at Williams to serve our Windows and other MS software license activations so we don’t need to hand out the windows activation keys!)
Anyway, with Rufus, your Windows ISO, and a fast external SSD drive (Samsung T3) use these settings to create your portable windows environment on a bootable external disk: