Thanks Duivels, thanks Ray
Here's what I've done:
I have a spare Gigabit Switch at home (a gift from KPN netherlands who I have to thank for that by the way), that I took.
I plugged the networkcable from my PC into the 1ste port
plugged my POHD into the second port
turned on the PC and the POHD. (so the network only had PC - Switch - POHD, no router or any other hardware)
placed my cursor on the network icon in the taskbar. It told me it was connected to WORKGROUP at a speed of 100Mbps.
Then opend the properties of the NIC. the link speed & duplex was on AUTO DETECT and I placed it on AUTONEGOTIATE 1000Mbps (the only Gigabit setting possible).
After that the connection was lost and the PC told me: one of the networkcables is not connected.

now I am confused.

I think time is catching up on my PC (a DELL Dimension 9150 bought in 2006) and it's time for a new one (but that will be a whole different negotiation

)
Anyway thanks for all your help guys.
The POHD works fine with my 2.5" drive connected to it so it's not a major problem. It would have been nice if it worked.
I need Windows 7 (read post about DLNA in HOW TO) to push content using mediaplayer anyway