The problem only exists on Bootcamp and not if the Apple Keyboard and mouse are connected to another Windows PC (for instance a Dell) directly. Also all other bluetooth devices besides the Apple keyboard/mouse (including those from other brands) seem to work fine. Conclusion: Does not seem like a general MS/Windows problem but like a driver. How to adjust Magic Keyboard brightness Apple has put lots of intelligence inside its system, which uses ambient light sensors to effectively manage display and backlit keyboard brightness.
Magic Keyboard
Lightning connector, built-in battery
Works with iOS devices with iOS 9.1 or later
Apple Wireless Keyboard 2011
Uses two AA batteries
Exposé and Launchpad function keys:
When using Apple Wireless Keyboard (2011) with iOS 4.3 or earlier, the function keys are limited to the Eject key. Update to iOS 5 or later to enable additional function keys.
Not all function keys that work on the Mac work on iOS devices.
In addition to Apple keyboards, many third-party Bluetooth keyboards that use the Apple keyboard layout work with iOS devices. Check with the keyboard manufacturer for additional information.
Learn more
Does The Apple Magic Keyboard Work With Windows 8
Learn about Magic Keyboard for iPad.
Mac equivalents of Windows keys
Many of the keys that you'd see on a PC have equivalent keys on an Apple keyboard.
Applications: This key isn't available on Apple keyboards.
Use the On-Screen Keyboard for other functions
If your Apple keyboard doesn't include the following keys, you can recreate them in Windows using the On-Screen Keyboard.
Use the Snipping Tool to print screen
To recreate the Print Screen and Print Active Window function in Windows, use the Snipping Tool.
If your keyboard isn't working as expected in Windows
Does The Apple Magic Keyboard Work With Windows Laptop
If your Apple keyboard works as expected in macOS but not in Windows, try these solutions:
Install the latest Apple software updates for Windows.
Install the latest Windows support software.
If you're using Microsoft Windows 10 N, install the latest Media Feature Pack.
Magic Keyboard Game
Learn more
Magic Keyboard 2 Windows 10
Microsoft provides a keyboard mapping article that describes using a Windows keyboard with macOS.
Use Microsoft Keyboard Layout Creator to find key combinations for the unique characters used by the language and region your Apple keyboard is designed to support:
Download, install, and open the Microsoft Keyboard Layout Creator.
Choose File > Load Existing Keyboard.
Select the keyboard you want to see.
Find the country or region name in the keyboard list that's followed by '(Apple)'.
Follow the instructions provided with the app. You can print images of the keyboard, including what keys look like when holding modifiers like Shift, Option, or Fn.