PTKaraoke is an open source, free and stand-alone karaoke player supporting midi files with lyrics (*.kar and *.mid). The search feature of your file manager (e.g. "My Computer") should be sufficient to find karaoke files in your database of karaoke files. When you associate PTKaraoke with these files, you can double click one to open it with PTKaraoke.
-Configuration dialog with bunch of settings (see right-mouse-button menu)
-OpenGL Hardware Accaleration.