Short story : just like the topic says . 
 
	Longer story : I'm a sucker for great audio and video ! No wonder it was my job since the early 1990s. I have an audiophile sound card (several , actually) .
 
	 On a clean Vista (with any official SP) the sound quality is fantastic ! Also, the video quality is full RGB and with rich and vibrant colours , but as soon as I install
 
	almost any update after the platform update , it becomes terrible , muddy , muffled , sandy sounding . Like it's having an obstacle (a pillow) , for example.
 
	Have you ever encountered something similar ?