Win 8.1 crash. Found Mozilla had lost all files afterwards.

Question

Been running T'bird for some years, a happy user.
Now on Win 8.1, with T'bird 31.5.
This morning, after normal shutdown last night, system would not reboot. After several retries, it said 'Repairing disk error'. Eventually it sorted itself out and started OK.
But when I started Thunderbird, it had lost all its profiles. Everthing else was working normally.
Tried to do System Restore, this failed.
I recovered the T'bird profiles (I back them up weekly) and T'bird was then now back to normal, so right now I'm OK.
BUT over the last few months I have had 2 or 3 system crashes with 'blue screen of death', which have recovered themselves but after each one, Thunderbird has not started normally, and I now suspect it's to blame for all these failures somehow. These have probably only been occurring since applying Win 8.1.
I note one or two similar other reports where the advice has been to compress the email folders regularly. I have always done this. I do have a lot of folders and handle a lot of mail traffic.
So I'm now starting to wonder. Any suggestions, please?

Answer 1

One further point, please no offense intended.
I lost access to my blogger account with Google several years ago, automated spam clearing bot of Google just deleted everything. Months passed before I managed to actually get my data restored. My point here is I now simply do not trust the "cloud" with my data. They make no substantive guarantees as to privacy, nor availability on a day to day basis or in the longer term. So I am wed to a local copy as well as a cloud copy. I think they cover different loss scenarios. My local copy might get wet or burned, the cloud might get hacked or the company just loose the data.
Some suggestions I can make that might help long term is create an exception for the Thunderbird profile folders in your anti virus program. They do not need to be scanned every time you move or delete a mail.
Turn off incoming mail scanning. Especially if your are using Nortons. Most Thunderbird users are using SSL or TLS. Most ISP's and free mail providers now require it. Nortons does not scan email over encrypted connections. So the functionality can only have a downside.