One of the nicest things about the taskbar is that when you hover your mouse over the icons in it, you can see thumbnail previews of all open windows for each of those applications. When you do so, there is a slight delay before the thumbnails appears. But you can make the thumbnails display more quickly by using a registry hack. 1. Launch the registry editor by typing regedit in the start menu search box and pressing enter. Do not select as ‘Run as Administrator’
2. Go to HKEY_CURRENT_USER\ControlPanel\Mouse
3. Double click MouseHoverTime. The default value you’ll see is 400 –> which means 400 milliseconds. Type in a new , smaller value –> let’s say 100 is good bet. Then click OK and exit the registry editor. You’ll have to log off or restart your computer for the changes to take effect.