1. A computer controlled method of indexing presentation files in a database comprising a plurality of presentation files stored on a computer-readable medium, each of the presentation files comprising a plurality of slides forming a presentation, each of the slides comprising words, the method comprising: selecting a slide in the presentation file; selecting at least one word present in the selected slide; counting a number of times the at least one word occurs in the selected slide; storing an identifier for the selected slide in a database of identifiers, the stored identifier having a link to the slide in the presentation file, the stored identifier comprising the at least one word and the number of times the at least one word occurs in the selected slide; and generating a query slide on which a search of the presentation files in the database is to be based, comprising: selecting at least one word present in the query slide; counting a number of times at least one word occurs in the query slide; creating an identifier for the query slide, the identifier comprising at least one word and the number of times at least one word occurs in the query slide; searching the database of identifiers for a slide having a stored identifier close to the identifier for the query slide; and returning at least one slide having a stored identifier close to the identifier for the query slide from the presentation file stored in the database of presentation files.