IN fact that is not what I meant its not the case......I am using window fx adds shadows to your windows and its the shadow that refreshes I don't think I have an explorer problem
but in your case its either not enough ram, slow ram or slow cpu............your problem is definetly hardware performance related........ because remmber explorer is being run as a seperate process......don't believe me play music and drag any explorer window real fast( shaking it for a sec) see what happenes to you music, restart with explorer as shell and you'll notice that your music isn't affected.