Sounds to me like you might have more than one issue.

1. Disable the slideshow in Windows 10 for the background image. it brings the wrong Thunderbird and firefox windows to the front when it changes images.

2. What anti virus program are you using?

3. Have you had better results on windows 10 in the past, or is the bad experience following update to windows 10?

Thanks for the reply Matt. Okay, first question - are you psychic?  :) How did you know I was using Windows 10?

1. When you say "disable the slideshow," do you mean the photos that come up when the computer goes into the sleep mode?

2. I am using Defender for anti virus. All others have been disabled and/or removed. Defender won't run if any other anti virus programs are running if I understand that correctly.

3. I've had MUCH better results in Windows 10 in the past. These issues have popped up in the past few weeks. AFAIK there hasn't been anything new added recently that should have caused this?

4. My computer just did an update and I had to reopen Thunderbird. Might be my imagination or a fluke, but Thunderbird seems to be behaving a little better now. Time will tell?

lensokoloff said

Thanks for the reply Matt. Okay, first question - are you psychic?  :) How did you know I was using Windows 10?

The forum software "grabs" the browser and operating system information your browser supplies to very web site you visit. If you look on the right of your original question on the forum is a more system details.

1. When you say "disable the slideshow," do you mean the photos that come up when the computer goes into the sleep mode?

Windows key + X Select control panel Select personalize Set background to picture or solid color

2. I am using Defender for anti virus. All others have been disabled and/or removed. Defender won't run if any other anti virus programs are running if I understand that correctly.

That would be correct

3. I've had MUCH better results in Windows 10 in the past. These issues have popped up in the past few weeks. AFAIK there hasn't been anything new added recently that should have caused this? 4. My computer just did an update and I had to reopen Thunderbird. Might be my imagination or a fluke, but Thunderbird seems to be behaving a little better now. Time will tell?

I have had a rocky time with Windows 10 on my Dell, and it is still not right. But I did write a blog post on what I found so far. http://thunderbirdtweaks.blogspot.com.au/2016/08/windows-10-and-thunderbird-firefox.html

Thanks again.

I don't have the Windows key on this keyboard. Is there a work around that? Never mind - found it. Right click on the desktop. I was already set with a solid color.

I have had zero problems with things since the updates and reboot last night. Let's hope all is well again. This problem is the first time I had any real issues with Windows 10.

The good news lasted about two days. It's doing it again. I begin typing a message and Thunderbird takes me back to the Inbox or some other folder and will sometimes move a message into the Archives.

Len

Perhaps go extreme...

Start *Windows'* safe mode with networking enabled - win10 https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode Still In Windows safe mode, start thunderbird in safe mode - https://support.mozilla.org/kb/safe-mode-thunderbird

Does problem go away?

lensokoloff,

what were your results please??

Thanks for checking on me Wayne. Thunderbird has been behaving reasonably well lately. I have not started it up in the "Safe" mode as you suggested yet. It seems like if I reboot Thunderbird every couple of days, it works okay. I've got my technical crew coking in over Thanksgiving - may ask them to take a look at this thread. Len

As a Window computer tech, my very first advice for any problem is usually, "Reboot and see if the problem still exists."

With Windows, I recommend rebooting the entire computer occasionally/often. I shut mine down at night.