After reading all you peoples tips I finally managed to get passed the 'Diskless Setup Failed' message. The MD set up for a long time and now wants to try to load the AV Wizard but it fails and gives a Blue screen with the message 'AVWizard Failed to setup X' I searched the forum for this problem and found a lot of threads about this problem. I've tried a number of possible solutions like manually installing the latest Nvidia driver on the MD but I get stuck with the same message again. Maybe I should mention that my Core has no Nvidia graphics card (it's an Intel MB with onboard graphics) because I'm not using my Core for video playback. I tried this thread
http://forum.linuxmce.org/index.php?topic=8460.msg56517#msg56517 and it worked fine but when I tried the 'dpkg-reconfigure -phigh xorg-server' it says: /usr/sbin/dpkg-reconfigure: xorg-server is not installed. Again I searched the forum for this but can't seem to find a solution.
I've got so far so i really would like to get to the AV Wizard. Any suggestions?
Thanks for the help so far