Vista - Microsoft Remote Keyboard (Infrared) on Vista

Hello,

I recently purchased a new Media Centre PC along with the Microsoft Remote
keyboard. Having set up the PC however I cannot get it to recognise the
keyboard.

The PC came with a remote control which does work so I know the Infrared
receiver is functioning, and as far as I can see the Keyboard is also
functioning (small red LED flashes whenever I press buttons on it). So I
don't know what's going on.

I understand that Vista is supposed to come with the drivers already
installed for this device, hence I cannot come online to download/re-install
this, and worse still - when I search the device manager to try and find the
infra-red reciever, nothing is available.

What should I do?