How can i undo "Remove bluetooth device" from kitkat? Before i was able to connect my moto X with my PC windows 7 64bits via generic bluetooth dongle. But i removed the pairing from my moto x and now its undetectable by the PC. Every time i turn on bluetooth on the PC and on the phone , then a turn on bluetooth on the phone and make sure its visible for all devices, its not detecting the pc and vice versa.

So, how can i undo the unpairing and make my phone and pc connect again ?

EDIT: I tryied to remove the registry key ( HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BTHPORT\Parameters\Keys ) from windows registry but no luck.
Make sure your both PC and PHONE are close to each other and the both Bluetooth are turned on and visible for all devices on both then go to your phone and search for devices and see if your PC will appear then try to pair then again.
There is no such a thing as 'undo pairing" you just need to pair them again.
Try that it should work usually if not check if there is any problem with your bluetooth on your pc in device manager.