Sony Vaio VPCF115 Buzz Squeal Audio Feedback

Bought this machine 3 days ago and no complaints so far. The "whine" or "screech" people have been talking about appeared almost immediately, but I fixed it as follows (2 days ago and no problems so far):

First, you can always stop it by muting the Mic (under the Mixer control at the bottom of the Speaker control at the lower right of the screen).

But if you want to leave the Mic on, go to Control Panel - Hardware and Sound - Sound - Manage Audio Devices. A window will appear with 2 devices, the Speaker/HP and the Digital Output. Click on the Speaker/HP device and the Speaker/HP Properties window will appear. Click the "Enhancements" tab. Check the "Pitch Shift" box and reduce the setting until the sound disappears.

For me, setting "Pitch Shift" at -1 worked fine, but I imagine you may have to shift it further if you are recording and/or playing at high volumes.