What irritates me the most is they don’t even bother to ask what to do with the bootloader when installing Windows, or at least the option is hidden behind some guru magic not supported by the installer GUI. Leave an old windows boot drive plugged in while doing a fresh install on another drive, and the installer happily uses the bootloader on the old drive without ever even mentioning it. Since it is so easy to make this mistake you’d think Microsoft offered a tool to move the bootloader to a different drive, but nope.