Magic Keyboard Failing to Switch Between Mac OS and Windows Bootcamp

Question

I frequently switch between Mac OS and Windows 10 but my Magic Keyboard seems to struggle to connect even though it's paired with both.

With Mac OS (when switching from Windows), if I click on it in the Bluetooth menu, it highlights briefly but never connects. However, if I plug it in to "charge" and then disconnect it, it will generally (but not always) connect.

In Windows (when switching from Mac), I can sometimes get it to connect if I tap keys during the loading process, but this seems silly and inconsistent. If it doesn't connect during Windows loading, I generally can't get it to connect at all without simply deleting it and re-pairing the device.

I read somewhere a while ago that this is because MacOS and Windows use different Bluetooth Addresses and that you can fix this problem by editing the Windows registry to match the Mac Bluetooth address. However, my Googling skills have failed me and I can't find the post anymore and I'm not even sure it works.

Has anyone else had this problem and can help me resolve it? Thanks!

Answer 1

This is a common bluetooth issue. If you are using, say, MacOS at the moment with your Magic Keyboard connected (by bluetooth), and you restart into BootCamp, many bluetooth devices including Headphones, Earphones, etc. do not reconnect automatically, which you already found out, is due to Mac Address.

Forgetting the device and reconnecting through settings (Windows) or System Preferences (MacOS) is faster than plugging it in and out of charging, and it works perfectly fine for me. You don't have to forget and reconnect every time you start your Mac; only those times when you boot into the other OS.

As for how to change the bluetooth addresses, follow these steps:

1. Make sure you have bluetooth icon on the menubar (if in Catalina), and if in Big Sur, simply click on control centre.
2. Hold Alt/Option and click on Bluetooth.
3. You will see your bluetooth address there. Write it down (exact) or write it in cloud based docs or similar to access it on Windows side.
4. It is discouraged to try to change the Bluetooth Mac Address, as answered here (Quora). Although, there is a third party app with which you can change the Mac Address of the Bluetooth module. (only do this if you are annoyed by forgetting and reconnecting the bluetooth devices repeatedly)
5. The third party app is Mac Address Changer for Windows. Install it, run it, enter the Mac Address you wrote down earlier, and click change. (There are images on the website too).

Thank You.