Why cant they find zeros files in the computer in the book Holes by Louis Sachar?

In "Holes" by Louis Sachar, the characters cannot find the zero files on the computer because the files are intentionally hidden or deleted by the warden. The story revolves around the mystery of the files, which are connected to the history of the land and the characters' pasts. This adds to the overarching themes of fate and the search for truth within the narrative.