Hello

Thank you for posting in Microsoft Community forum.

You might need to manually edit the registry to fix the Bluetooth pairing issue. This involves copying the Bluetooth pairing keys from Linux to Windows.

Here's a simplified version of the process:

• Pair the device in Linux and note the MAC address.
• Install chntpw in Linux to access Windows registry keys: sudo apt-get install chntpw
• Access Windows System Drive in Linux and navigate to the Bluetooth registry keys: cd /[MountedDrive]/Windows/System32/config sudo chntpw -e SYSTEM cd \ControlSet001\Services\BTHPORT\Parameters\Keys ****
• Copy the pairing key from Windows and paste it into the corresponding file in Linux: sudo nano /var/lib/bluetooth/[Unique ID]/[MAC Address]/info ****
• Restart Bluetooth service in Linux: sudo service bluetooth restart

Additional Tips:

• BIOS Update: Sometimes, updating the BIOS can resolve hardware compatibility issues.
• Check for Interference: Ensure there are no other devices causing interference with your Bluetooth signal.

Best Regards,

Wesley Li

1. Pair your bluetooth device(s) in Linux.

2. Reboot into Windows, and pair your same bluetooth device(s) in Windows.

3. Run regedt32.exe. Navigate to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BTHPORT\Parameters\Keys"

4. Right-click on the "Keys" folder in the lefthand pane of the path above, and select "Export." In the pop-up dialog, change "Save as type" to "Text files," be sure that the "Export range" radio button "Selected branch" is selected, and save the file to your choice of name and location.

   • Note 1. For this purpose it's convenient if you've already configured a drive partition that's shared between your two OS, but it's not absolutely necessary, as you can use a thumb drive to transfer the file as well.
   • Note 2: If you have trouble exporting the folder, right click on the folder, select Permissions, and add Users to the groups that can read and edit the folder.

P.S. If you don't see keys then go on the [HKLM\SYSTEM\ControlSet001\Services\BTHPORT\Parameters\Keys] folder right click and click on 'Permissions' , add your windows user and give it 'Full Control' You should be able to see the pairing keys then.

5. Now reboot into Linux.

6. Open a command prompt in Linux type sudo caja (if you're not running Linux with MATE, you may have a different file manager; substitute as necessary) and enter your password at the prompt. This will open a file manager with SU rights, so handle with care ... I'm not responsible if you brick your system!

7. Navigate to /var/lib/bluetooth. Inside of this folder you will see one or both of two things -- either a single folder named with a single MAC address (of your computer's bluetooth adapter) or multiple folders, each with its own MAC address, for each paired bluetooth device (the MAC address will be in the format XX:XX:XX:XX:XX:XX). If you find only the single folder, folders with those individual MAC addresses will be inside the first adapter folder.

8. Open the folder containing the MAC address of the device you wish to pair in dual-boot mode. Inside that folder will be one or two files ... the one you care about is the "info" file. Double-click on it and it will open in a text editor with SU rights -- that is, you'll be able to edit it and save it. (by the way, if you're not sure which device you're looking for, the "info" file contains the plain-English device name, so just open each one in turn till you find the right one).

9. Open a separate (non-SU) instance of your file manager, and use it to open the text file you saved from Windows in another pane. When you double-click on that file, Linux may ask if you want to execute or edit it ... choose to edit.

10. The Windows registry export will contain multiple stanzas (one for each device) that look like this (don't worry, I've changed to a bogus MAC and key):

Value 1 Name: 0008e024d45e Type:
REG_BINARY Data: 00000000 31 c0 08 fa 4f 7b d2 4c

• 6f e1 7d ba 32 29 a9 a7 1À.ïO{ÒLoá}ºQ)©§

11. Find the stanza containing the value on the "Name:" line which corresponds the MAC address of the file you have open in the first (SU) pane. Note that in the Windows files, the format of the MAC address uses lower-case letters instead of upper-case, and there are no colons.

12. Your Bluetooth pairing key is the string in the line that begins "00000000" and ends with a bunch of gibberish. Don't copy either the zeros or the gibberish, just the string in-between containing the 16 hex codes with the dash in the middle.

13. Insert that key into the "Key=" line in your "info" file. You can copy and paste if you want (I did), but you need to change lower-case letters to upper-case, and delete all spaces and dashes. In the example above, the resulting line will look like this:

Key=31C008FA4F7BD24C6FE17DBA3229A9A7

14. Now save the file, repeat for any additional devices. Reboot into Windows, your device should now work. Reboot into Linux, it should also work.

Good Luck

Why does this happen?

Basically, when you pair your device, your Bluetooth service generates a unique set of pairing keys. First, your computer stores the Bluetooth device's MAC address and pairing key. Second, your Bluetooth device stores your computer's MAC address and the matching key. This usually works fine, but the MAC address for your Bluetooth port will be the same on both Linux and Windows (it is set on the hardware level). Thus, when you re-pair the device in Windows or Linux and it generates a new key, that key overwrites the previously stored key on the Bluetooth device. Windows overwrites the Linux key and vice versa.

Bluetooth LE Devices: These may pair differently. I haven't investigated myself, but this may help Dual Boot Bluetooth LE (low energy) device pairing

How to fix

Using the instructions below, we'll first pair your Bluetooth devices with Ubuntu/Linux Mint, and then we'll pair Windows. Then we'll go back into our Linux system and copy the Windows-generated pairing key(s) into our Linux system.

1. Pair all devices w/ Mint/Ubuntu
2. Pair all devices w/ Windows
3. Copy your Windows pairing keys in one of two ways:

   • Use psexec -s -i regedit.exe from Windows (harder). You need psexec as normal regedit doesn't have enough permissions to show this values.

     1. Go to "Device & Printers" in Control Panel and go to your Bluetooth device's properties. Then, in the Bluetooth section, you can find the unique identifier. Copy that (you will need it later). Note: on newer versions of windows the route to the device's properties is to go through Settings -> Bluetooth & devices -> Devices -> More devices and printer settings
     2. Download PsExec from http://technet.microsoft.com/en-us/sysinternals/bb897553.aspx.
     3. Unzip the zip you downloaded and open a cmd window with elevated privileges. (Click the Start menu, search for cmd, then right-click the CMD and click "Run as Administrator".)
     4. cd into the folder where you unzipped your download.
     5. Run psexec -s -i regedit.exe
     6. Navigate to find the keys at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\BTHPORT\Parameters\Keys.  If there is no CurrentControlSet, try ControlSet001.
     7. You should see a few keys labels with the MAC addresses - write down the MAC address associated with the unique identifier you copied before. Note: If there are no keys visible after pairing, you likely need to add permissions to read (right click -> permissions) Keys\
     8. For convenience export it as a text file. click file -> export -> as text and save it to a shared partition/cloud.

   • Use chntpw from your Linux distro (easier). Start in a terminal then:

     1. sudo apt-get install chntpw

     2. Mount your Windows system drive in read-write mode

        • To find the drive use sudo lsblk -o NAME,FSTYPE,SIZE,MOUNTPOINT,LABEL. Depending on how your dual boot is setup its usually the first ntfs partition on the drive with /boot/efi. Note the NAME.
        • sudo mkdir /mnt/c
        • sudo mount --read-only /dev/<NAME> /mnt/c
        • To safely unmount the drive sudo umount /mnt/c
          • If you need to try a different drive or when finished all these instructions

     3. cd /[WindowsSystemDrive]/Windows/System32/config

        • on Windows 10 the root folder is "Windows", on Windows 7 it is "WINDOWS"

     4. chntpw -e SYSTEM opens a console

     5. Run these commands in that console:

        > # If there is no ControlSet001, then try CurrentControlSet
        > # on Windows 7, "services" below is lowercased.
        > cd ControlSet001\Services\BTHPORT\Parameters\Keys
        > ls
        # shows you your Bluetooth port's MAC address
        Node has 1 subkeys and 0 values
          key name
          <aa1122334455>
        > cd aa1122334455  # cd into the folder
        > ls  
        # lists the existing devices' MAC addresses
        Node has 0 subkeys and 1 values
          size     type            value name             [value if type DWORD]
            16  REG_BINARY        <001f20eb4c9a>
        > # Get the value of the REG_BINARY entry
        > hex 001f20eb4c9a
        => :00000 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX ...ignore..chars..
        # ^ the XXs are the pairing key
        

     6. Make a note of which Bluetooth device MAC address matches which pairing key. The Mint/Ubuntu one won't need the spaces in-between.  Ignore the :00000.

4. Go back to Linux (if not in Linux) and add our Windows key to our Linux config entries. Just note that the Bluetooth port's MAC address is formatted differently when moving from Windows to Linux - referenced as aa1122334455 in Windows in my example above. The Linux version will be in all caps and punctuated by ':' after every two characters - for example AA:11:22:33:44:55.  Based on your version of Linux, you can do one of these:
   • Before Mint 18/16.04 you could do this:

     1. sudo edit /var/lib/bluetooth/[MAC address of Bluetooth]/linkkeys - [the MAC address of Bluetooth] should be the only folder in that Bluetooth folder.

     2. This file should look something like this:

        [Bluetooth MAC]   [Pairing key]                 [digits in pin]  [0]
        AA:11:22:33:44:55 XXXXXXXXxxXXxXxXXXXXXxxXXXXXxXxX 5 0
        00:1D:D8:3A:33:83 XXXXXXXXxxXXxXxXXXXXXxxXXXXXxXxX 4 0
        

     3. Change the Linux pairing key to the Windows one, minus the spaces.

   • In Mint 18 (and Ubuntu 16.04) and later you may have to do this:

     1. Switch to root: sudo -i (In old versions of Ubuntu, 'su -')

     2. cd to your Bluetooth config location /var/lib/bluetooth/[bth port MAC addresses]

     3. Here you'll find folders for each device you've paired with. The folder names being the Bluetooth devices' MAC addresses and contain a single file info. In these files, you'll see the link key you need to replace with your Windows ones, like so:

        [LinkKey]
        Key=B99999999FFFFFFFFF999999999FFFFF
        

5. Once updated, restart your Bluetooth service in one of the following ways, and then it works!

   • Ubuntu, Mint, Arch:

     sudo systemctl restart bluetooth 
     

   • Alternatively, reboot your machine into Linux.

   • Note: do not attempt to connect before restarting Linux. A failed connection attempt may invalidate the Windows key.

6. Reboot into Windows - it works!

Typically Bluetooth pairing keys are stored by the OS, so although Linux and Windows share the same Bluetooth MAC address (appearing as a single device), they keep track of pairings independently from each other.

After you've paired the headphones with Windows, the headphones stored the new link keys for the computer's MAC address and discarded the old ones previously created by the Linux pairing (with the assumption that the computer did the same). However, Linux still thinks it's paired – it has the old keys stored in /var/lib and attempts to use them when connecting.

You have to completely remove the headphones from bluetoothd and pair them again. (This will make them stop working on Windows.)

I used to have an article about manually copying the link keys from Windows Registry to the Linux bluetoothd configuration so that the same pairing could be shared across both operating systems, but the article was written for WinXP and BT 2.0, so it most likely needs an update for Windows 10 and/or the new pairing protocol that came with Bluetooth 4.x – last I checked, the keys are a bit different now.

Same symptoms as in the question happend to me on a Dell XPS 13 after installing Wacom software for a Intuos BT S tablet.

Solution for me was disabling Bluetooth in the BIOS, rebooting and enabling it in the BIOS again, as is said in this thread: https://ubuntuforums.org/showthread.php?t=2348005

The issue has been resolved by Intel recently !
Windows drivers where somehow interfering with the device firmware.
Just follow those instructions, from Windows :

1. Download Intel latest drivers for Windows
2. Disconnect your computer from Internet to prevent drivers getting installed via Windows update
3. Uninstall your current driver on Windows through device manager and check "delete local driver"
4. Shutdown Windows
5. Boot Windows (don't forget, must have no internet access)
6. You should see “Unknown device” in device manager on reboot
7. Install the latest driver previously downloaded
8. Boot to Linux
9. Boot to Windows
10. [optional, if anything wrong happen] Dump the content of HKLM\System\Software\Intel\Bluetooth key contents to a text file immediately after any issue occurred