When you hover your mouse over a Taskbar button for an app with open windows, a thumbnail preview of those windows pops up. By default, there is a slight delay before the preview appears. With a simple Registry edit, you can eliminate that delay, or even turn off those thumbnail previews entirely.

Control Taskbar Thumbnail Previews by Editing the Registry Manually

To change the speed of (or disable) taskbar thumbnail previews, you just need to make a quick edit to the Windows Registry.

Standard warning: Registry Editor is a powerful tool and misusing it can render your system unstable or even inoperable. This is a pretty simple hack and as long as you stick to the instructions, you shouldn’t have any problems. That said, if you’ve never worked with it before, consider reading about how to use the Registry Editor before you get started. And definitely back up the Registry (and your computer!) before making changes.

RELATED: Learning to Use the Registry Editor Like a Pro

Open the Registry Editor by hitting Start and typing “regedit.” Press Enter to open Registry Editor and give it permission to make changes to your PC.

In the Registry Editor, use the left sidebar to navigate to the following key (or copy and paste it into the Registry Editor address bar):


Next, you’ll create a new value inside the Advanced key. Right-click the Advanced key, and then select New > DWORD (32-bit) Value. Name the new value ExtendedUIHoverTime .

Double-click your new ExtendedUIHoverTime value to open its properties window.

In the properties window, you have a few options:

  • Instant Thumbnail Previews: If you want to disable the thumbnail preview delay so that they appear instantly when you hover your mouse over a taskbar button, change the ExtendedUIHovertime value to 1.
  • Increase Delay: If, for whatever reason, you’d like a longer delay, enter any value here up to 5,000 milliseconds (5 seconds). Values above that start to act a little flaky.
  • Disable Previews: To eliminate thumbnail previews altogether, enter a value of 30,000. You can still see thumbnail previews by clicking the taskbar button, but automatic previews will not appear.
  • Restore Default Delay: To restore the default delay, set the ExtendedUIHoverTime value to 0 (or just delete it).

In our example below, we’re disabling previews by entering a value of 30,000.

RELATED: How to Restart Windows' Explorer.exe (Along With the Taskbar and Start Menu)

When you’re done, you can close Registry Editor. You’ll need to sign out and sign back in to Windows (or just restart Windows Explorer) for the changes to take effect.

Download Our One-Click Registry Hacks

If you don’t feel like diving into the Registry yourself, we’ve created some registry hacks you can use. Just download and extract the following ZIP file:

Change Taskbar Thumbnail Previews

Inside, you’ll find three files:

  • Instant Taskbar Thumbnail Previews: Sets the ExtendedUIHoverTime value to 1 and eliminates the delay before taskbar thumbnail previews appear.
  • Turn Off Taskbar Thumbnail Previews: Sets the ExtendedUIHoverTime value to 30,000 and prevents thumbnail previews from automatically appearing.
  • Reset Taskbar Thumbnail Previews to Default: Sets the ExtendedUIHoverTime value to 0, restoring the Windows default delay for thumbnail previews.

Just double-click the file you want to use, and accept the prompts asking whether you’re sure you want to make changes to your Registry.

RELATED: How to Make Your Own Windows Registry Hacks

These hacks are really just the Advanced key, stripped down to the ExtendedUIHoverTime value we talked about in the previous section, and then exported to a .REG file. Running the hacks just modifies the value in your Registry. And if you enjoy fiddling with the Registry, it’s worth taking the time to learn how to make your own Registry hacks.

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Walter Glenn is a former Editorial Director for How-To Geek and its sister sites. He has more than 30 years of experience in the computer industry and over 20 years as a technical writer and editor. He's written hundreds of articles for How-To Geek and edited thousands. He's authored or co-authored over 30 computer-related books in more than a dozen languages for publishers like Microsoft Press, O'Reilly, and Osborne/McGraw-Hill. He's also written hundreds of white papers, articles, user manuals, and courseware over the years.
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