iTunes does not make it easy to find solutions to problems, especially with Windows. On this blog, the most read posts are about my struggles with iTunes and iPods. Lately I have been struggling with iTunes 7.0 The solution to garbled output is not well documented, in my opinion. So here is what I found.
iTunes and Quicktime share functionality and most of the time they cooperate well. To solve the problem of poor quality, unlistenable music in Windows iTunes 7.0 you must change your Quicktime Audio playback settings. Duh.
Here is what i did.
Open preferences page for Quicktime. (Edit, Preferences)
Click on the Audio tab.
In the "Sound Out" Box: select the output format supported by your audio hardware. Change to:
Size: 16 bit
I had never changed these settings before, but with iTunes 7.0 this seems to be what works.