I also downloaded the bootcamp drivers. On titled Unable to use Apple Bluetooth USB Host Controller in. Bluetooth windows driver from the Parallels KB. Download the latest driver for Bluetooth USB Host Controller, fix the missing driver with Bluetooth USB Host Controller.
Parallels Desktop 12:
Apple Bluetooth USB Host Controller is not present in my virtual machine device list. There are no bluetooth related options under Devices ->External Devices
There are Microsoft Bluetooth devices present in Windows Device Manager:
Parallels Desktop 11 and/or bellow:
I am unable to use Apple Bluetooth USB Host Controller device in my virtual machine. After I mark this device under Devices ->External Devices, device appears in Device Manager as Bluetooth USB Host Controller with exclamation mark:
Unable to find specific bluetooth devices (for instance, calculator, GPS, radio devices) on the Windows side.
Bluetooth devices are not detected inside the virtual machine.
Cause
Parallels Desktop 12
Apple Bluetooth USB Host Controller support is very limited in Parallels Desktop (or any other virtualization solution) due to stability reasons.
Assigning Apple Bluetooth USB Host Controller used to cause all connected wireless (Bluetooth) devices to disconnect from host. Therefore behaviour was changed in Parallels Desktop 12 where an ability to connect Apple Bluetooth USB host controller to the virtual machine is not present by default.
Resolution
NOTE:Apple Bluetooth USB Host Controller isn't optimized for work in Windows guest systems. There might be possible issues when using Apple Bluetooth Controller in Windows virtual machine. Parallels recommend one either to use Share Bluetooth device with Windows option in VM settings or to use separate USB-Bluetooth device when working with Bluetooth in Windows virtual machine.
NOTE: As Parallels Desktop uses Shared Bluetooth functionality now, most of wireless devices should work fine when shared between Mac and Windows side. However, in case any Bluetooth device does not work in VM, it is recommended to acquire an external Bluetooth USB controller and connect it directly to VM, then to configure Bluetooth and connect the device
Parallels Desktop 12:
In Parallels Desktop 12 one can share Bluetooth functionality between both Mac and Widnows side.
Simply open virtual machine configuration > switch to Hardware tab > then select USB & Bluetooth. You can disable sharing of all Bluetooth devices between Windows virtual machine and Mac side.
In case Share Bluetooth devices with Windows option is checked two Microsoft Bluetooth adapters are emulated on Windows side.
Parallels Desktop 11 and/or bellow:
NOTE: Bluetooth devices on the Mac side will be not available, while Bluetooth Controller is passed in the VM. To return it back to the Mac, untick Devices ->External Devices->Apple Bluetooth USB Host Controller.
Check the bit version of your Windows: How to determine whether a computer is running a 32-bit version or 64-bit version of the Windows operating system
Install Bluetooth driver on your Windows virtual machine following the link:
General Information: Apple official webpage for support software
For 32-bit Windows: AppleBluetoothBroadcomInstaller.exe
For 64-bit Windows AppleBluetoothBroadcomInstaller64.exe
Check that on the Mac side that the Bluetooth is on.
In the virtual machine Configuration open Hardware ->USB & Bluetooth -> untick Bluetooth Devices.
When virtual machine is running, at the Mac menu bar click on the Devices ->External Devices -> tick Apple Bluetooth USB Host Controller.
On the Windows side go to Control Panel ->Hardware and Sound ->Devices and Printers.
Right click on Bluetooth USB Host Controller ->Bluetooth settings -> tick Allow Bluetooth devices to find this PC and click Apply, OK.
Click Add a device.
Now, all Bluetooth devices will be displayed and paired with the Windows correctly.
NOTE: If you have an exclamation mark on one of the Bluetooth devices with description: Code 10. 'The device cannot start', please perform the following:
Download and run HotFix.
10.1. Check all necessary system requirements for corresponding version of Windows VM.
Go to Start, in the Search box type devmgmt.msc and hit Enter (rerutn) -> right-click on the bluetooth device with exclamation mark -> Update driver software.
10.4 If none of the above works, you may want to use another virtual machine which already has these drivers installed and copy applebt* in C:WindowsSystem32DriversFileRepository from the working machine to malfunctioning.
10.5 After that, you need to update drivers manually and point it to the aforementioned folder.