Q: Why isn't OS X Spotlight or Finder finding a file by content that I know exists? I've got several files in a few folders that I know contain a word, say "foo".  I've manually found some of those files, but neither Spotlight or Finder's search is showing those files as matches nor any of the others that certainly exist.  I assume that the files need to be indexed by the OS.  Is this true?  If it is, how do I "fix" it?

A: It might be that indexing is broken on your drive for some reason (perhaps a corrupt file, etc.)
You might want to follow the steps outlined in this Apple support article to reindex the files on your volume.
What sort of files contain this word? Perhaps the files are in some kind of binary format that isn't indexed.

A: Spotlight doesn't index every file in your system. Depending on where it is or what kind it is, you may have to recur to Terminal or 3rd parties such as Find Any File or EasyFind, which can search for content

