My machine was dying a miserable death today, as it has done often lately, and it was all down to a bug between Bluetooth software and Skype. What I noticed is literally hundreds of the same process "BluetoothHeadsetProxy.exe", with a new one spawning every few seconds.
My first problem was working out how to kill all the processes in one go - this turned out to be very simple, using the following command:
taskkill /F /IM BluetoothHeadsetProxy.exe
The next problem was working out why the processes were starting up, and I found the answer on StackExchange as usual.
To get rid of the problem: