Hi there Udo - let me try to help you ...
and the XXHighEnd logo in the library windows with the Directory name under it and a black background.
This is correct, and the logo (actually an X for "nothing") tells that no coverart was found with the particular album (which will be in the directory you mentioned). Now :
Click that "coverart" picture (hence select it) and click Load. Now in the Playlist Area the tracks will appear.
Another means would be to drag tracks from normal Explorer (or a complete folder) onto the Playlist Area.
There are several more means, but this should get you going.
Of course click Play now (on a first selected track).
The Atom is suitable, but it should be a dual core actually. A hypertheading will work also, but not as good.
With a normal single core you will be experiencing problems at the preprocessing needed (XXHighEnd is a memory player).
Associating XXHighEnd with music files will never work (at least not now) because indeed there is no Install. So forget about that at this moment.
Let me know if this helped you.
Peter
PS: Notice the context menu (rightclick) on many objects, like that "coverart" (the X in your case).