The Windows 10 bootloader likes living on the... edge. One wrong step and it's toast, two wrong steps and not even recovery can help you :D I found installing

The Windows 10 bootloader likes living on the... edge. One wrong step and it's toast, two wrong steps and not even recovery can help you :D I found installing Windows 10 in legacy (not UEFI) BIOS mode makes it more stable, and the various recovery tools (sfc, bootrec, etc) actually work. Strange, but this is Windows, so maybe not that strange.