Here is another speed up tweak for Windows 7. By default Windows 7 task bar thumbnail preview gets delay of about 400ms. This guide shows you how to remove that delay and faster load the thumbnail previews of task bar. This process is same as the one we published previously in speed up of Windows XP start menu, that requires you to works with Windows registry.
Press WinKey+R, to run a program and type regedit to run Registry Editor.
In the Windows Registry navigate to HKEY_CURRENT_USER\Control Panel\Mouse on the left hand side and after double click on MouseHoverTime in right hand side.
In the 'Edit String' message box, enter the preferred delay at the 'Value data' field. You can set it as 10 or 0. then Click OK and exit the registry editor.
Please restart the computer to see the results.