The latest BootCamp drivers fail to support Function keys on Apple internal laptop keyboards in Windows 10. To fix this, one can use an older driver.
- Download the older BootCamp drivers from https://support.apple.com/kb/DL1720?locale=en_US
- Extract the ZIP file contents.
- In
BootCamp5.1.5621\BootCamp\Drivers\Apple
, runAppleKeyboardInstaller64.exe
.