If you use System 7.0 or 7.1, Apple’s new Sound Manager should improve the performance of QuickTime movies. Open the “Sound Manager 3.0” folder on the CD and drag both Sound Manager and the new Sound control panel onto your System Folder icon. Click OK if your Mac asks you if it can put these items where they need to go. Then click OK if your Mac asks you if it can replace an older version of the Sound control panel.