To print a score, you use the menu: [File|Print], use a windows shortcut <ctrl-P> or the print button 
on the buttonbar. The usual windows print-screen will guide you further through the printer and page selection.
To print a single part from a score you may deselect the 'score' box in the score dialog and select the desired part.
Printing using a non-licensed installation will require you to enter a sequence of letters and digits correctly.