I have noticed for years how my Mac laptops are very quiet. When I go into a conference with someone who has a Windows laptop you can constantly hear hear the

I have noticed for years how my Mac laptops are very quiet. When I go into a conference with someone who has a Windows laptop you can constantly hear hear the hd making noise. It wasn't until when running vmware that my hd would make noise that I put it together. Any idea what Windows is doing?