Here are 3 fixes for you to try. You may not have to try them all; just work your way down until you find the one works for you.
Method 1: Update Driver Manually
Method 2: Update Drivers Automatically (Recommended)
Method 3: Use Microsoft Mobile Device
Step 1: Go to Device Manager. Locate Bluetooth Peripheral Device under the category Unknown devices.
Step 2: Right-click one of the devices and click Update Driver Software
Step 3: Click Browse my computer for driver software
Step 4: Click Let me pick from a list of device drivers on my computer.
Step 5: If you are asked to select from a list, please select Bluetooth Radios
Step 6: Then in the next window, it will show a list of drivers with Manufacturer in one list and driver model in another. Click Microsoft Cooperation.
Step 7: You might see more than one drivers with the name Windows Mobile-based device support. You can choose the latest version of them. Then press Next to continue.
Step 8: Ignore the warnings and keep pressing Next and then Finish in the end. If the installation goes well, you will be able to see the message that device driver is successfully installed.
Step 9: In Device Manager, expand Bluetooth Radios option, it should display one more item which says Windows Mobile-based device support.
Step 10: If you have already added the device in your Bluetooth device list and it is not working, you need to remove it and add it to the list again. You might need to restart the computer to make the changes take effect.