Those reading need to know what did Win10 do after the BSOD did it do system restore or system file fix? Restore will wipe clean all data after the last Win10 working saved image - this will mean nothing after that timeline will exists.

https://support.mozilla.org/en-US/kb/recover-lost-or-missing-bookmarks

Ahh! This is a tough nut to crack and shocking time lost. Windows spent a day and half night RESTORING...so I presume from your post I have lost all, but I thought there was a firefox .sqlite file with the undeleted bookmarks ? Surely this should be accessible and importable ? I managed to get the sidebar/menu bar running but my another worst is I don´t work with some Qzerty kezboard characters. For some reason under language preferences this won´t settle. That is a windows issue-. Unfortunately with thea home edition 20/1H2 version, MS has treated us very badly. Result;I am no windows fan.

rJ

No if your system did a complete system restore anything after the last working image that Win10 saved is gone and there is no recovery since the system wipe clean anything that could be recovered or found.

Windows spent a day and half night RESTORING

What data did you get back on your computer? Windows generally takes better care of your Documents folder and desktop than your application data. Was it able to preserve those?

Sometimes when you start a Windows Reset it will ask if you want Windows to save your data. Do you recall anything like that? You could take a look for the backup folder that can be created by that feature:

C:\Windows.old

If you find that folder:

Set Windows to show hidden files and folders:

https://support.microsoft.com/en-us/windows/view-hidden-files-and-folders-in-windows-97fbc472-c603-9d90-91d0-1166d1d9f4b5

Then explore that folder up to this point (if it exists):

C:\Windows.old\Users\<username>\AppData\Roaming\Mozilla\Firefox\Profiles\

If you find recent data there, please pause and we can suggest how to resurrect your saved files.

....if you want Windows to save your data. Do you recall anything like that? Well, Nup. All one gets is the MS dupe caption that a system reset is being done. Anyway, don´t all snigger, but with the behavior of the Notebook and it´s lousy performance, my memory is better than it, and I managed to recollect all the web links and, "voila" into the bookmarks. Now then it actually asked me to override the old links....and Yes, is the answer as the old may be corrupt. Consider this problem done....but it took a beer or two. All sorts of peculiarities with Win10 20HD2 home edition , the ACER backlight now functions after a couple of years absentia, which tells me it was a BIOS problem too.

Cheers fjscher2000 and others, I´ll send beers over.

Be forewarned, but unrelated; the original culprit to the internecine problems was nothing to do with FireFox, but the was the RealTek audio driver. At one´s peril, several sites suggest that those users suffering poor sound quality to get into the Device driver, nudge down into the sound section and delete the Realtek driver software. If Win10 is working properly (rare) it automatically detects the omission (from the small Speaker icon) when hardware changes are detected and will reload..My advice...becareful. I retried this and it worked no issues.

rJ