Playback volume

I have been working on a piece for months. Every time I have played it back on my computer speakers, it has played back at normal volume which I could adjust up or down with the volume knob of the speakers. Now, all of a sudden, the playback volume has decreased enormously even when I crank up the volume on the speakers. Is there a setting in Musecore to adjust the universal volume. I can, of course, go onto the mixer and adjust individual parts, but that's not the problem. The problem is the total volume. For other programs, the volume has not changed--only on Musescore! Help!