Thanks, but it doesn't seem like a good bet that MS will let that stand indefinitely, and a Win8.1 install with that sort of trouble would be even more obnoxious than 10.
The way I understood your initial post the main objective was--
" The point is, getting the Windows install to under absolutely no circumstances interfere with the Linux install's operation"
Doing a dummy run on a spare drive could test that option...............
Only if I install Linux before Windows, though, if I'm understanding you correctly (and doing it in that order with only one drive is a mess for more reasons than the rest of this). For install-time interference, worst-case is the main drive can't be in the system while Windows is being installed, but that's not a huge problem. Post-install interference would mainly be about bootloaders, and only applies if the two OSes have to share a drive. I don't use a bootloader - my mobo firmware knows where to find the Linux kernel. GRUB jumped the shark at some point, and either dealing with that or having to F11 to UEFI to pick boot target is the first hurdle. The bigger problem is that the two OSes would have to share an EFI partition (currently /boot) on an ongoing basis, and I don't trust Windows to not wreck something in there.
Windows will only install on an external USB device if the device is Windows to Go compliant. Even if the device is Windows to Go compliant, you still need Windows 10 Enterprise for this to work, other editions don't support it. Otherwise, you'll have to install it on an internal devicehttps://docs.microsoft.com/en-us/window ... o-overview
Fairly sure I've installed it on external hard drives before without any of that.
Thanks, both of you, that's one of the points I'm most curious about. Considering other stuff with activation, I don't think they should have any reason to lock down this particular case (using normal Windows as WtG would still fail due to hardware differences), but it's tough to tell with Microsoft.