Starting in Windows 10 (version 1607), I am unable to pair my Bluetooth-enabed serial device to PCs. When this issue occurs, I can search for discoverable Bluetooth devices from my device and find the PC I want and attempt to pair to it. The Windows PC will give the usual "tap here to to add device" prompt, but instead of displaying the PASSKEY window where I can enter my device's PASSKEY, it only opens the Bluetooth Settings window, so I am unable to enter my PASSKEY. PCs are using the Microsoft Bluetooth Enumerator and various drivers (Intel, Dell, Realtek, Marvell, etc.) and are configured with an incoming Bluetooth serial port. My device utilizes the serial port profile (SPP) of the Bluetooth specification and will always initiate discovery. This is the methodology of pairing for all Windows PCs. PCs that wish to connect to my device must respond to the Discovery request from my device and must support a standardized PASSKEY for authentication and encryption (The PASSKEY can be set by the user on my device). Using this method, my device will send out a Discovery. The PC will respond with its identification including the friendly name. The user selects the desired PC and my device will request to complete this trusted pair and challenge the PC to produce a passkey. If the PASSKEY that the PC responds with matches my device PASSKEY, then my device will create this trusted pair and complete the connection process. This worked perfectly in previous versions of Windows 10 and all preceding Windows operating systems going back to Windows XP. I have updated to the latest build (14393.576) and the issue remains -- no window received to enter the PASSKEY.