I'm about ready to pull my hair out over this. Ever since the update to Firefox 45, I keep losing my security and privacy settings. When I set Privacy tab > History to "Remember history" the settings stays put during my session, but as soon as I close and reload my browser, it has been changed to "Custom settings" with "Remember search and form history" unchecked. If I just check that box, again it retains it during the current session, but when I've reloaded FF it has reverted back to being unchecked again. Same with Security > "Remember logins for sites" where I want that box checked, but as soon as I close and reload FF it is unchecked again. Once I set both of those settings to remember, it works fine. And the logins are all there as saved passwords. I can access them through the Options page. It all works -- I just can't get Firefox to retain these particular settings. I eliminated all my add-ons, one by one, and finally ripped out FF completely, including the Windows directories. I did a virgin installation of FF, with no add-ons and the settings all the default installed values, but it still did it! I have put most of my add-ons back (since I need these for the work I do and for sanity ;-) ) but it seems they are not part of the problem. The only thing that changed it was when I rebooted my computer in Safe Mode with Networking. Amazingly, it didn't do it then, but as soon as I rebooted in regular mode, it did it again. I thought maybe my antivirus was doing something, so I wrote to Trend and asked them if this could possibly be something their program was doing, and they insisted it couldn't be. Just to be sure, I changed the antivirus to one I had paid for but wasn't using (ESET) but there's been no change since I swapped out Trend for ESET. Trying to figure out which program is loading on startup is not something I'm technically comfortable doing. I did try exiting a few background programs to see if it helped but no luck. I know my way around a computer better than the average person but I'm no expert. I'm running Firefox on Windows 7 64-bit. Please note, this ONLY started with the Firefox 45 update, and I've been using Firefox for MANY years. Is anyone else reporting this or have an idea what's causing this?? It's driving me crazy, since I have to redo the settings every time I load FF. Many thanks in advance for any help with this.