Just as with Windows 7, when you hover over Taskbar icons, previews of open windows appear. These don't normally snap onscreen but fade in and out of view, and if you move between Taskbar icons the previews become animated. If you don't care for the Windows 8,1Taskbar animations and would rather save time by disabling them, the following tweak does so:
1. Access the "System Properties" Control Panel. One way to do this is by pressingWindows + R, entering sysdm.cpl and pressing Enter.
Accessing the Windows 8.1 "System Properties" Control Panel
2. When the "System Properties" multi-tabbed dialog box appears, click the "Advanced" tab.
3. Underneath "Performance", click the "Settings" button.
Accessing Windows 8.1 Performance Options
4. When the "Performance Options" multi-tabbed dialog box appears, make sure the "Visual Effects" tab is selected. Uncheck "Animations in the taskbar".
Disabling Taskbar animations in Windows 8.1
5. Click "OK" on the dialog boxes to close them.
Source from http://malektips.com/
