Word file lost apparently during update

I responded to messages coming up telling me urgent updates were available, though I couldn't see what could be so urgent that hadn't been a problem (at least to me and my fairly basic use of the system) for a good few years. I downloaded all the updates and it told me I had to close down and restart to activate them. However, for a number of reasons I didn't want to do that till the following day. But it wouldn't let me postpone it for more than 4 hours at a time. Among other things I had several Word docs open and being worked on. I noticed after 4 hours that when the reminder came up again I had to reset it within a specified time or it would automatically close down and restart whether I wanted it to or not. A little later I left the PC on and went out. It put itself to sleep after, I assume, the normal specified time. When I returned several hours later I activated it again and started working. But clearly I'd left it rather more than 4 hours as it suddenly closed down without any warning. When it restarted it did at least reopen the Word docs I'd had open - except one, which it said it couldn't open. When I tried to open it I discovered it had entirely disappeared from my Documents folder. I tried System Restore, but that said it wouldn't affect files, and it didn't. Or certainly that Word doc remained lost. So can anyone suggest what might have happened to that doc and why. And also, why the system has been set up to close down automatically when I didn't want it to. Seems slightly arrogant to assume that Windows updates must be more important than whatever I happened to want to do before closing down and restarting. Certainly losing that file is extremely inconvenient and makes me want to find someone I can legitimately shout at!...

Well, I got a notice telling me to read and follow some instructions. I read 'em, but I'm afraid I didn't understand 'em. So whether anyone's seen this I don't know, as it may not become public till I do as I'm told. Anyway, it doesn't matter as, although the Word doc didn't come back when I did the system restore and then closed down and restarted, it did the NEXT time I closed down and restarted. Which just confirms my view that IT is completely random and illogical. So I'll mark it as Solved, since my particular problem is solved - though my query as to what the hell happened isn't solved at all..........