right click on the sound icon in the tray,
select playback devices,
select your active playback device (the one with the tick),
select enhancements
and tick the box to disable all sound effects
ok the boxes till back to desktop
run Media player and see if it is improved if not then disable the enhancements in WMP (equaliser SBS etc),
if this corrects the problem I would then go to your Laptop/Motherboard/sound card manufacturers site and check for the latest drivers
unfortunately this bug is known to the manufacturers and to Microsoft but apart from this workaround is yet to be solved
I know it's a strange one I have a desktop and a laptop with exactly the same sound chip and driver and only get the problem on the laptop even running through the same speakers