It means the hard disk was bypassed during POST. To rectify, you autodetect
wow, I wish I had the psychic ability to know their CMOS settings.
if it really was being "bypassed" then setting the drive from "<None>" to <Auto> would fix it.
There was no hardware changes before this inability for windows to detect the drive. Your essentially saying that computers will decide randomly, "hey, I'm bored. I know, I'll stop recognizing this particular drive for absolutely no rhyme or reason until the user goes through a useless and unproductive set of CMOS options that leave them back where they started but somehow manage to redetect the drive".
Doubtful.
The issue is almost certainly an OS issue.