Fixed? Nevermind. It seems to have been an issue with my graphics card updated its drivers. Video games weren't working either, but now with the drivers restored, the previews are back. Thanks. :D
I installed Windows 7 yesterday and was loving. But after installing some updates today my previews on the taskbar have disappeared. Or rather, they're still there, but they're no-longer visual previews, it just gives me the text of the document that's there. What happened? I really want these...