Yes, the program I was referring to is locate32...was not sure if that was only one version's name.
And the link for mozbackup is:
http://mozbackup.jasnapaka.com/
Calbre has always been very stable for me. It hasn't just made files disappear on whatever computer I am running it on. One gloomy prospect is the computer has a virus that has hurt the file structure.
If it is a matter of things being improperly changed, maybe you could do a system restore to put pointers back as they ought to be.