To save a temporary playlist with a different name
Click NowPlaying or MediaLibrary, click the Select Playlist Options button at the bottom of the Playlist pane or the Details pane, respectively, and then click SaveAs.
-or-
On the File menu, click SavePlaylistAs.
Type the new name for the playlist, and then click Save.
Notes
In MediaLibrary, you can also right-click the Now Playing category, and then click Save as New Playlist.
If you have created a temporary playlist from an existing playlist, you can also overwrite the existing playlist with the temporary playlist by clicking Save on the Select Playlist Options menu in NowPlaying or by clicking Save Playlist on the File menu.
By default, playlists are saved with a .wpl extension. You can also save playlists with the following extensions: .m3u, .asx, .wax, or .wvx.