To resolve this issue:
- Right click the speaker icon in the taskbar
- Click Playback devices
- Click on the Audio device/speakers currently enabled (default device notated by green check mark)
- Click Properties button below
- Click the Enhancement Tab
- Uncheck all of the boxes in the Sound Effects window
- Click the "Disable all sound effects" or "disable all enhancements" checkbox
- Click OK
- Reboot the Computer
solution credit: http://corey.degrandchamp.com/2010/11/25/fixed-windows-7-sound-popping-cracking-skipping/