Did this fairly quick project because 1) I wanted a quick way to see what Win11 would be like on different devices without the hassle of installing it, 2) I use the Enterprise ISO, and it's easiest to get the Insider download when a Windows version is complete but before Microsoft releases the next new build, & 3) because the Win 2 Go drive I was using had been created with Rufus, which does not support secure boot, which Win11 requires. That last part worried me the most, since while it's easy enough to turn secure boot on/off, at least in many BIOS, I wasn't sure how Win11 would respond if you forgot to turn it back on after a lengthy session of troubleshooting for example. During a Win11 fresh install setup did *try* to turn secure boot on, so I assume Win11 has that capability -- I was lucky since this PC's motherboard has a backup BIOS and reset itself, but most of our other devices do not have that.
Windows To Go drives are relatively simple... you have a FAT32 partition with the boot files, & the partition with a regular install of Windows, both on a MBR [not GPT] disk. You could copy an already installed copy of Windows to the external drive, or do it the official way, applying an image. Windows is distributed in an image file that's in a special, Microsoft format -- it's not unlike the .zip files we're all used to. These image files have the .wim extension, or .esd for the encrypted versions -- note: downloading an ISO you'll usually get a .wim file, but use the Media Creation Tool & you'll usually get an .esd file, and that can make a difference depending on the software you use. The Microsoft tool for working with .wim files is called DISM, and most every Win2Go tool will use it. Where the software tools Really come in is creating the boot files -- they are overly complicated with little to no documentation, so these tools are worth it. Microsoft removed their own Win2Go creation tool from Control Panel years back, and copying the files from an older version of Win10 no longer works. This time I used the tool in AOMEI's free vesrion of Partition Assistant.
The result is secure boot capable / compatible, though it's also a little bit weird... it might be because I used the Enterprise ISO, but there's no listing in File Explorer for Control Panel for example. I also had to manually add the AMD display driver, whereas the Win10 Win2Go did it automatically. Once it was done I used Partition Assistant again to unhide the boot partition, then edited it with EasyBCD -- the result works, but booting to this PC I see 3 identical listings for the Win2Go drive, where I'd normally see two, one UEFI & one without. Now, the reason I edited the boot files [BCD]...
I was concerned that Win11 might not work so well on some devices, as well as Win11 just sometimes doesn't work so well on its own, so I added back my existing Win2Go copy of Win10. I shrunk the Windows partition to 65GB [just over the Win11 requirement], and restored a backup of the Windows partition from the Win10 Win2Go drive to that now empty space. I then used EasyBCD to add that copy of Win10 to the Win11 boot menu, and the drive works to boot into either copy of Windows.
