I searched the forums and found 2 threads about this problem. The first one tells me to add a "symbolic link" to detect the media. I can't image what this should be but heres a quote:
So, if you have a hard drive on your LMCE box with media you can get it to show up inside video folder like this:
sudo ln -s /media/hda5 ./hda5
And heres the link to the thread:http://forum.linuxmce.com/index.php?topic=1347.0
And there was another thread, that refered to the wiki:http://wiki.linuxmce.com/index.php/Usage_Intro
But I cant find there any information that is relevant for me. They're talking about "public/private" configuration of the files the whole time, not how to make the media visable first.
I hope somebody can tell me more precisely what I have to do...