You can disable the Playlist Window from opening via an Addon.

Thanks. That's it. There was about 40 playlist windows all piled together and the X was really hard to see. Closed each one. Thanks again!

You may be referring to the Playlist windows, which can be closed using the x in the titlebar of the playlist window.

I got a new laptop and installed MM5. I closed the right panel. When I entered names of playlists, a new column appeared on the right side that showed the name of the playlist on top, then the message "Drag and drop or send tracks to the playlist to populate it." This same massage was overwritten in the column with each new playlist. I can't get rid of it. Any suggestions?