Xbox 360 / Media Centre connection

Hi again all!

Ok, unistalled Nero (wasn't using it anyway!) but still I have the same
problem which is as follows......

I get the 8 digit code off of the 360 and start the Xbox 360 setup on the
Media Centre on the PC.

It states that the "Xbox360 cannot be contacted" & "Setup is unable to
contact Xbox360".

Now, I have ensured that the necessary .exe programmes have been enabled via
my Norton firewall, so now I'm stumped.

I click help on the set-up and it states that an Extender is not detected
(which I believe is also the 360)

I'm not a complete idiot (hence able to work out the .exe programmes) but I
really don't know what to do next...........
If it's any help to you guys, I have my Xbox 360 downstairs in a completely
different room to my PC. I connect to Live by an ethernet connection cable
via my BT Voyager 205 ADSL Router.

I have no probs with my Live connection, so why can't I get the "extender" /
360 / PC to talk and let me browse my music etc??

Thanx for your time and comments!

Hexen666