External microphone / realtek audio device

Hi there,

I've been trying to use an external microphone on my computer because the built-in one is pretty bad but the computer doesn't seem to find it. When I plug it in the audio jack on the right, Realtek detects it and asks me what to do with it but when I browse the device manager I can't find it. I've also tried setting it up through skype and realtek but I don't get to chose another microphone as default device. It appears nowhere but on this pop up information bubble saying a device has just been un/plugged.

Could anyone help me with that?
Cheers