In 2018 we started using “Windows to Go” on externally boot-able disks to provide the “windows” half of a dual-boot mac. To make this work you need to do the following …
1) Purchase really fast external SSD drives of sufficient size. We choose 250 GBs Samsung T3 drives like:
https://www.samsung.com/us/computing/memory-storage/portable-solid-state-drives/portable-ssd-t3-250gb-mu-pt250b-am/
2) Create your windows environment on a computer that has a removable internal SSD drive. Check this carefully before you begin as most new hardware is coming with SSD system drives soldered to the motherboard! Also be sure that your image is “sysprepped”! See additional tips on preparing a system for imaging/cloning at: https://sites.williams.edu/lj1/labs/windows-10-imagining-tips/
3) Once sysprep has run and shutdown the system, remove the internal hard drive from the computer. Using a sata to usb hard drive docking station like: https://www.amazon.com/s?k=sata+to+usb+Hard+Drive+Docking+Station&i=electronics&ref=nb_sb_noss_2
Mount the sysprepped, internal drive on a different computer that has Microsoft WAIK installed. (Use the version of WAIK that matches the Windows version you are cloning!)
4) Attach another external SSD drive just regularly formatted for windows data. This will be a “Scratch” drive.
5) Run Windows update on your computer for any updates that could interrupt your process!
6) Set your Power and Sleep settings to NEVER sleep either computer or display. This process can take a long time!
7) Now determine all your drive letters. I will use C:\ for the current system where everything is attached, E:\ for the internal drive to take an image from in the drive dock, and S:\ for the scratch disk.
8) Create some directories. You will want to create:
C:\MyImageDir …. to receive the wim image you will be creating
S:\Scratch …. to hold the scratch files
9) With WAIK installed, the internal drive from your system to be cloned, and your scratch drive all attached ….
Find the Windows Kits in the Start Menu then open “Deployment and Imaging Tools Environment” with right-click and “Run as Administrator”. This opens a command window with elevated privileges.
10) To create the wim image in the opened command window you opened above, enter this command:
DISM /Capture-image /ImageFile:C:\MyImageDir\MyImage.wim /CaptureDir:E:\ /Name:"SomeNameForMyImage" /ScratchDir:S:\Scratch\
11) Wait a really, really long time ! Eventually you will see “Saving Image …” with a percentage in that command window.
12) Once that wim image is complete, you can use it as input to the Windows To Go disk creation process.