Bluetooth Keyboard Pairing Problem

When the battery of my HTPC’s bluetooth keyboard needed replacement, it somehow lost the connection during that process (I think I pushed the connect button by accident at the wrong time, or something). Not a big deal, I thought…

Plugged in a wired mouse, navigated to the Bluetooth configuration panel and tried to let it pair again (this is on a Windows 10 Pro 1803 system, by the way).

But strangely enough, the dialog offered indeed the usual instructions (“Please enter the PIN to confirm”), but didn’t actually provide any PIN at all!

After trying several times, rebooting the computer, updating drivers and cross testing (successfully paired the keyboard with my Android tablet and connected my smartphone to the PC via Bluetooth), I was running out of ideas and started searching the internet.

As it turned out, I was not the first or only one with such a behavior under Windows 10.

The tip that finally resolved my issue was found in a Microsoft Community thread: Can’t pair Bluetooth keyboard - “Check the PIN and try connecting again.” (Page 2), which in turn referenced Bluetooth Mouse asking for passcode.

In short:

  1. Open the registry editor (via regedit.exe)

  2. Locate Computer\HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Bluetooth\ExceptionDB\Addrs
    The keys below that key represent the MAC address of the Bluetooth devices; find the correct one and delete that key (or if, like me, you only have a few entries there — the real one plus a few test devices — just remove all the keys there, instead of wasting time to somehow find out the MAC address of your bluetooth keyboard).

  3. After that, you can immediately try pairing the device once more: A PIN should now be generated again.