Taskbar Thumbnail Preview Tweaks

The Aero theme in Windows 7 gives users the ability to preview thumbnails of opened applications when hovering over the respective icons in the taskbar. You can tweak both the size and the loading time of thumbnails by modifying the registry as shown below:

To start the registry editor, type regedit in the Start menu search text box and press enter.

To change the size of thumbnails you need to add the following REG_DWORD in the registry key HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Taskband:

  • Key: Software\Microsoft\Windows\CurrentVersion\Explorer\Taskband
  • DWORD (32-bit) Value name: MinThumbSizePx
  • DWORD Value data: (# size in pixels)

If you find that thumbnails are too small then you may start with a decimal value of 300.

There is a delay load time when you hover over thumbnails which is set to 400 milliseconds by default. You can decrease this delay time by modifying the following REG_SZ in HKEY_CURRENT_USER\Control Panel\Mouse:

  • Key: Control Panel\Mouse
  • String Value Name: MouseHoverTime
  • String Value data: Default = 400 (milliseconds)

Change the above String value data from 400 to say, 100 milliseconds.

You must restart your computer for the changes to take effect.

A word of caution – incorrectly editing the registry may severely damage your system. The above modifications are intended for Windows advanced users who are familiar with the registry editor. Users are also reminded to backup the registry before making any critical changes.