So, you have a disk case with disk inside that is connected to a USB-A or USB-C and you want to make your disk bootable so Windows 11 will start first from this outside this and then from internal disk if outside disk is not connected. Here is how to do it.

• Format USB disk
• Start CMD as administrator and follow these commands – be very careful when choosing your USB drive:
  • diskpart
  • list disk
    (select disk X ← your external SSD)
  • clean
  • convert gpt
  • create partition primary
  • format quick fs=ntfs label=”WIN2GO”
  • assign letter=E
  • exit
• Mount your Windows 11 ISO so you can see it as new drive, suppose it will be on letter D
• Execute this command:
  • dism /apply-image /imagefile:F:\sources\install.wim /index:1 /applydir:E:\
• Make external drive bootable
  • bcdboot E:\Windows /s E: /f UEFI
• restart PS, enter BIOS and enable USB Boot and move USB Storage device to the top

• boot windows 11 from usb drive
• make bootable outside disk
• win2go
• windows to go