upgrade to macOS high sierra, bootcamp win10 disk exists but can not prompt when turn on the power I just upgrade my mac mini to macOS high sierra.
Before, when I turn on the power, there is the option for me to choose boot from Windows 10 or macOS.
but right now, it boots and enters macOS directly.
I checked and found that BOOTCAMP disk still exist,
all content of the bootcamp hard disk appeared and nothing removed.

Is there any way to activate/import the existed bootcamp disk and add the option for Windows 10/macOS when turn on the power?
If you just want the option when needed, hold the alt/opt key doing boot, it’ll let you choose which OS you want to boot...