In Windows 7, when you hover over an application in your task bar, a preview is generated showing the contents of the application window.
Another option just displays the names of the windows.
Somehow, I've turned off the preview and it only displays the window names. How do I change it back?
Right click on Computer » Properties » Advanced system settings » Advanced tab » Performance settings. Here, uncheck/check 'enable desktop composition'.
This will disable/enable preview of windows on the taskbar.
None of the Aero Peek settings or registry edits work.
WARNING: this will result in many other changes and cannot be easily undone.
You need to enable Aero
Right click on your desktop -> personalize
Edit : Or you have recently installed an application that dosen't suport Aero, so you can't reenable it.
For me this was solved by copying (or rather screenshotting) all settings in "personalization", then activating the "Windows 7" theme, applying all settings again and then saving that as a theme.
Right Mouse Click on the taskbar, go to properties and on the first tab, make sure 'Show window previews (thumbnails) is checked.
