1. I just bought ATI HD 4650 and sound interface (because my onboard sound not working).

2. Then i start having problem with my sound quality, but it just great when i play mp3s. But when i play any video with audio( for example youtube), the sound start to DISTORT and CRUNCHY.

3. After almost 24 hours try and error, and googling all over the net. I manage to narrow down the problem and now im quite sure that the ATI High Defination Audio Device driver that causing the "distort" sound when i play a video with music.

4. I try to uninstall my ATI graphic driver and the ATI HDA driver also went away, and my sound became superb NO PROBLEM. But i have to reinstall my graphic driver back, and the ATI HDA comes back and the problem occur again. Is there any way to completely KILL this ATI HDA driver? I try to disabled it / uninstall the driver alone at device manager, but it didnt work because it keep reinstall automatically after i reboot. Please help T_T

The ATI high definition driver wont be used if you dont use the HDMI port from your video card.
Alternatively, you can adjust the volume for each application with "volume mixer".
IF your OS is vista or w7.

Windows XP should have some similar options.

when installing the ATI display driver, don't use "EXPRESS". use "CUSTOM instead. then untick the HDMI/DP audio driver.