Question: I really love the preview feature of the Windows 7 taskbar. There's only one reason I don't use it more often -- it takes a relatively long time to display the actual window.

There is a registry trick ([widely found on Google](http://www.pctools.com/guides/registry/detail/17)) to reduce the delay used by general menus, and make the submenus open instantly when hovered upon. I'm wondering if there's a similar trick that can be used for the Windows 7 taskbar's previewing.

Answer: 
Here's a link to a similar registry trick : <http://www.techtalkz.com/windows-7/516236-how-modify-mouse-hover-time-windows-7-a.html>

1. Run Registry Editor in Windows.
2. Go to `HKEY_CURRENT_USER\Control Panel\Mouse`
3. Adjust the `MouseHoverTime` value (which is in milliseconds and defaults to 400). For example, you can set it to 0.
4. Restart your computer so that the new setting can take effect.

Enjoy :)
Run Regedit, go to `HKEY_CURRENT_USER\Control Panel\Mouse`  

adjust the `MouseHoverTime` data which is in miliseconds. Default is 400.