Hey JD - Plenty of advice about this across the net, not much of it is accurate. You can definitely turn the previews off via GPEdit, but that is not available in Home Premium (assuming that is your version?).

There are a couple of registry hacks too. One which extends the delay time of the preview window, which I believe would work. Extend the delay time to something like 20 seconds and the preview would then not display until you actually hovered the mouse cursor over a button for 20 seconds or more.

The second hack, which is supposed to turn the feature off altogether, was meant for Vista. It works sometimes in Win7 and often times not, depending on build number.

My suggestion would be to utilize a freeware from the Windows Club called 'Taskbar Thumbnail Tweaker'. It doesn't require installation (single executable) and includes an option to disable the previews: http://www.thewindowsclub.com/taskbar-thumbnail-tweaker-resizer-for-windows-7-released

I tried it and it definitely works - no problems. Simple to reverse any changes too.

Cheers...Jim