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?