(Buzzz!)
Don't use Apple Disk Utility to prep a drive for a windows install. Apple has no track record of playing well with others re drive layouts, and there are many arcane aspects of drive format.
Wipe the Windows target drive by copying zeros over the first few megabytes, (cat or dd /dev/zero to target) so the partition table is zapped. You want to see "This drive cannot be recognized do you want to initialize it?"
Use the Microsoft Windows Media Creation Tool to build your installer drive.
Disconnecting other drives is safe thing to do but Windows doesn't usually screw up.
The Windows installer should offer a default install on the blank (effectively) target drive. Unless you have a specific need, say making room for a Linux install, don't fiddle with the layout.
The rest of the story is appropriate BIOS settings, covered elsewhere.
If that doesn't work, likely a HW issue.
OTHER NOTES
Linux installer has learned to play nice with Windows.
Windows installer at least doesn't usually wreck Linux installs any more. Windows diskpart sees the world as purely Windows — its pure lore.
Install Windows then Linux.
Mac doesn't deal with either, and they don't grok Mac. Don't mix and match. It can be made to work at a deep tech level but too much nerding out. Mac Disk Utility is more open minded re layout standards but there are edge cases and no one works hard to perfect a Mac-controlled Windows drive. At same time cross platform file system support for Apple, esp APFS is very tricky and lacking.
OpenCore is one more variable, where Ubuntu Linux installer (Unity) may step on EFI/Bootx64.efi, especially on an NVMe unrelated to Linux install.
Down the road if you want to mess around with a Windows layout, for example to multiboot Linux, use Linux GParted as drive tool. It has good awareness of layout edge cases, and can set Windows part types,
resize and move partitions reliably (but not Mac volumes tho) Windows uses several different partitions at least one of which doesn't tolerate being moved without having to repair a connection to it: the Windows Recovery Partition. This can be fixed using Windows tools but is a PITA.
Thanks
@c-o-pr,
I believe it turned out to be a combination of the NVMe being present and needing to use one of the Rufus install USBs. I'm booted up into Windows 11 Pro as I write this, so all is good now - but I'd like to leave some breadcrumbs for any others that hit this snag.
I tried using the Windows Media Creation Tool, but that didn't result in sucess any more than any of my other attempts had. It might well have met with success, though, had I pulled the NVMe out prior to using it. The weird thing was that I've pulled the NVMe out before without success, so there must be one or more other variables at play.
I wasn't actually relying on the Apple Disk Utility to prep the drive in the end. Instead, I'd just use diskpart to do that while booted off of a Windows USB. Generally, my process there was to delete any extra partitions (other than the 300MB EFI partition that I had), then reformat the EFI as FAT32 and use Custom Install in the Windows installer to pick the unallocated space. I was doing a lot of deleting partitions 2, 3, & 4 on that disk since each failed attempt would leave those behind.
Another thing I did, and I'm not really sure if this made any difference or not, but maybe it did - I disabled just about everything I could in BIOS (had to keep the USB driver, of course), plus disconnected absolutely everything other than the keyboard, mouse, and USB stick.
Bottom line - for me, success looked like this:
1. Make Rufas UEFI install stick in VirtualBox 6.1.40 (needed at least an 8K NTFS block size) using a genuine Microsoft Win11 ISO
2. Disable as much stuff as possible in the BIOS - even audio and Wi-Fi/Bluetooth, no need to take any chances. I did leave the on-board Ethernet though, which helped during the install.
3. Disconnect absolutely all drives other than the target - which for me meant unhooking to SATA HDDs and pulling an NVMe drive out.
4. Boot to the Rufas Install Media and use Shift+F10 to get to a command window and run diskpart
5. Confirm the only disks present were Disk 0 (the target disk) and Disk 1 (the USB)
6. Use diskpart to delete all partitions on Disk 0 except for the 1st one, which is a 300MB FAT32 EFI partition. Reformat that one to make sure there aren't any stray files left over from the previous attempt.
7. Use Windows Installer to do a custom install on the unallocated space on the target drive.
8. Sit back and watch the mayhem, cheering madly when it passed the point I always got stuck on.
9. Give the system an appropriate name (Mine begins with S and ends in atan)
10. Come here and post.
Thanks to all the generous folks who helped me out with this! You guys are amazing!
Now to see if plugging the NVMe back in gets me to OC and the ability to boot into either Monterey or Windows 11!
