This is a weird one and I'm hoping there's a reassuring explanation. I had Firefox and Sumatra PDF open, nothing else on Win 10. I switched from Sumatra to Firefox (1 tab open), searched for something, and Firefox froze, and after a while Windows gave me an option to terminate the non-responsive program, which I did, and Firefox closed. But the hard disk was active 100% afterwards, and everything slowed to a crawl, and I couldn't even get the Task Manager to open, so I did what I haven't done in many ages, killed the power. (Experience tells me a memory leak.) After the restart Firefox opened, a bit slowly, to the last open tab. Browsed a bit. All is fine. Closed Firefox, opened it again, and now I'm logged out of every website, including the saved preferences, e.g. of Wikipedia. It's worth pointing out that I closed Sumatra just fine, but it too lost the history (it remembers which page I last viewed for the opened documents). Since Firefox was the one to freeze, and to work fine afterwards, logged in and all, then lose all after opening it again, I'm not sure what happened, and if there's anything I can do. Sorry for the lengthy post, but basically: Is that expected after a freeze/recovery?