OS: Win7 Pro x64
Laptop: Lenovo x240
Dock: Lenovo ThinkPad Basic Dock - Port Replicator 
Monitor 1: AOC 21.5", E2243FW (VGA)
Monitor 2: Lenovo 21.5", LS2223 (DVI)


When hovering the cursor over any pinned/unpinned icon on my taskbar, the preview icon that pops up is quickly fading away (as quickly as it starts up, seemingly with the reverse animation as when it appears).

While holding Alt and pressing Tab to cycle through open applications, the window of icons will disappear (and if I continue to hold Alt and press Tab again, the window will reappear and will start me back at the first icon).

This problem will "randomly" not happen after rebooting and then will begin happening again.

Attempts to resolve:

  • Fully run the Windows and ThinkVantage System Updates
  • Removed all unnecessary peripherals (keyboard, external CD drive, ect)
  • Changed Visual Effects from "Let Windows choose what's best for my computer" to "Adjust for best performance", as well as Custom (all unchecked, and tried solely checking "Save taskbar thumbnail previews")
  • Used one monitor at a time (tried both monitors separately). Lowered the resolution and refresh rate of each monitor. Removed all external monitors.
  • Used the laptop completely removed from the dock and external peripherals
  • Safemode


I have seen some registry tweaks that can extend hover time which, as you can imagine, I'm hoping to steer clear of having to make any changes like this. No other Windows 7 machines I've used have had this issue.

My guess is that an application isn't stealing Window's focus since I'm able to leave the Start menu up for an infinite amount of time without it minimizing.

Edit: I notice the amount of time icon previews stay visible varies - they could last 3 seconds, 5 seconds, 10 second, half a second, ect.

  • Have you tried turning off Aero Peek and turning it back on again?
    – Kinnectus
    Jul 1 '14 at 11:53
  • Yes, as part of my "Changed Visual Effects" exercise.
    – root
    Jul 1 '14 at 12:27
  • Does this happen when booting in Safe mode?
    – harrymc
    Jul 1 '14 at 14:32
  • Yes, as mentioned in my "Attempts to resolve" section.
    – root
    Jul 1 '14 at 15:50
  • Sorry, missed that. Note that although you haven't edited the registry, some application could have done that. Could you use regedit to look in the registry key HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced and tell us if you have entries for ThumbnailLivePreviewHoverTime or ExtendedUIHoverTime. If you do, let us know their values.
    – harrymc
    Jul 1 '14 at 15:55

RESOLVED!!! I have the same issue, similarly, all suggestions never work... the following is my detailed symptom:
When you move over the application icon on the taskbar (that has application opened), you would expect a preview to appear. In this case, although the preview window appears, it will simply auto-disappear (i.e. closed by itself within a very short period of time, e.g. 1 sec). This behaviour is also evident when you use Alt-Tab.

Very frustrating!

Editing the registry, etc, does not help for me. Setting the aero peek (enable or disable or a mixture of those) also does not help.

My Solution
After trying different ways, I found out that it was due to the battery charging setting!!! - A ridiculously stupid cause.

I believe this is a bug, but if it is not categorized as such, then I supposed the aero peek might be taking too much battery or whatever that the battery setting was configure to close it.

I am using Lenovo T440s. So all I did was to change it back from "Optimize for battery health" to "Always full charge (Start when below 96%; stop at 100%)".

Hope this helps those who find the other solutions not working.


Regards, Jacky [BTW, my original sharing post is here (Taskbar aeropeek preview and Alt-Tab auto close on Windows 7), told to answer directly here instead.]

  • Nearly a year later and we've reached a solution, thank you Jacky. We had discerned this was a power setting issue but had always overlooked that setting. For clarity, to check/change this option: Open the Lenovo Power Manager (switch to the Advanced view using the button in the top right), switch to the Battery tab, click Battery Maintenance, select "Always fully charge (Start when below 96%; stop at 100%)". My Charge Mode had been set at "Custom charge threshold" with Start charging at 15%. Switching to Always fully charge had this problem resolved immediately without having to restart.
    – root
    Apr 6 '15 at 12:11
  • Just to be safe, before making the above changes, I had hit the "Restore default settings" button on the Power Plan tab. Worth mentioning incase that also played a role in the result.
    – root
    Apr 6 '15 at 12:12
  • Confirmed. Fix just now worked for me. Holy cow, seriously, Lenovo? (And Dell?)
    – JohnL4
    Dec 6 '16 at 17:10
  • NOTE: (I wanted to add this as an edit of my previous comment, but my five minutes ran out.) There might be another approach. I removed the Lenovo Power Manager toolbar from my taskbar (right-click taskbar, under "Toolbars", deselect Power Manager), restored the "Optimize battery health" setting and it still seems to be working. So far. So I think it might have more to do with toolbars updating their taskbar display every second than the actual battery hardware/software. Might explain the fact that Dells are also reported as having trouble.
    – JohnL4
    Dec 6 '16 at 17:17
  • Never mind, looks like I was wrong. Back to my normally-scheduled outrage.
    – JohnL4
    Dec 6 '16 at 17:34

I was having this problem and it occurred after I changed my battery charging mode to "Optimize for battery health"

After changing it back to "Always fully charge" the icon hover time is now permanent again.

  • I wish I had read this sooner, this option wasn't as straight forward to find as you'd hope. This did work though, as mentioned in the answer I marked as the solution.
    – root
    Apr 6 '15 at 12:47

As we have tried in the comments above setting just about every registry entry that is known to affect icon preview, all without success, the only solutions left are the ones relating to the integrity of Windows itself :

  • Repair Install to fix Windows components without harming installed applications
  • Reinstalling Windows and then installing the applications one by one and checking after each
  • For completeness sake I mention sfc /scannow, although it was tried above
  • +1 and awarded bounty for helping to check each key individually, but still optimistic that a more telling solution will come up with time
    – root
    Jul 8 '14 at 13:16

I had the same problem with my Dell XPS 15z. it turns out that the disappearing taskbar previews only occurs when I am operating with a fully charged battery and line current (battery charger)connected. Once the line current is removed (operating on battery) or operating with line current and a charging battery, the previews remain visible as long as I hover over the icon.

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