hi dleolion, do you have Trend Micro Passwordmanager or Dashlane installed in your list of programs on the system? if so, please uninstall it from there if you're not using it...

Philipp

As I mentioned in my post, I do not use Trend Micro Security Password Manager (or the Dashlane you mention).

yeas, i have seen that - put there might be a difference between not using a program and the program not being installed. quite a number of users of trend micro security products here reported, that the password manager got installed silently and without their knowledge. so in case you are using trend micro, please douple check in your system control panel that their password manager isn't showing up there (or uninstall it otherwise).

Philipp,

I decided to check deeper into my Trend Micro. I have never used the Password Security feature, so I thought I'd just see if it had been installed without my knowledge.

I checked the Trend Micro App (on my Windows 10 machine) and did not find an uninstall for the Trend Micro Password Manager (meaning it wasn't installed). And, there was no "Add on" showing in Firefox for the Trend Micro Password Manager. However, one step further, I went to Control Panel, Programs & Features, and there was Trend Micro Password Manager in the list, so I uninstalled it.

This obviously was NOT the problem, as I turned off my computer and upon restart of the computer and Firefox, the "remember logins for sites" checkbox was AGAIN unchecked.

Do you have any other recommendations? I have never had a problem with this for all the years I've used Firefox, until just recently (last week or so) since the upgrade to the newest version.

no, i have no other explanation, this will almost certainly be caused by this unwanted trend micro addition (what happens after firefox is shutdown & during a reboot is outside of the control of firefox - firefox has no automatic processes that start in the background or would perform any changes). please see if it is working as expected after another reboot - if not, you should try getting in contact with trend micro's support as well

Philipp,

Just before I read your last post I decided to check again by rebooting the computer one last time.

I am happy to report that after the second reboot the "remember logins for sites" checkbox remained checked!

For others out there with the problem, if they are using Trend Micro and even thought they haven't activated the Password Manager feature, they need to go into Control Panel, Programs (& Features in Win 10), look for Trend Micro Password Manager in the list and uninstall it. Then reboot the computer at least twice!

Thanks for you prompt and helpful advice, Philipp!!! Mark me as solved, and happy. :)

Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen or hold down the Shift key) to see if that has effect.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/
• http://www.7tutorials.com/4-ways-boot-safe-mode-windows-10

There is software like Advanced SystemCare with its Surfing Protection feature that can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

• http://kb.mozillazine.org/Preferences_not_saved
• https://support.mozilla.org/kb/Preferences+are+not+saved

I do not use Trend Micro Security, but I cannot save the option 'Remember logins for sites' Why is there no 'Save/Cancel' button on the Security page? Is it silently saved when I close it?