Weird computer happenings

Just off the heals of my recent internet access woes this morning I had another strange thing happen. I came back to my computer after being away and the screensaver wouldn't go away. I pushed the mouse around and punched the keyboard but still nothing. I tried cntl+alt+del but that had no effect so I eventually I just hit the reset button. I wasn't paying too much attention to the reboot process but when I did look up my screen said "operating system not found". I've never seen that before...ever! At first I thought maybe my drive crashed or something like that. I never had that happen before but I figured maybe this is what it would be like. I hit reset again and watched it go through the bootup process and eventually got the same "operating system not found" message again. I just shut it down after that and pondered my next move. I'm handy enough with computers and hardware so all sorts of things were going through my head. The prospect of more downtime and the time I'd need to take getting up again didn't make me too happy. After a short time I fired up my computer again and it booted without a problem. Windows scolded me for shutting down improperly and scanned my C: drive before starting up but that was all. I've been at my computer for most of the afternoon writing emails and such and it's like nothing ever happened. Just in case though I'm backing up the data on the drive to my second drive. A drive crashing may be just around the corner for me.