How do I remove cheques that have cleared long ago, so that when I go to my 'Recon' tab, it only shows more current cheques?

Also, is purging history recommended periodically? Can I assume that once the history is purged, it is no longer available? Or does it only purge it from certain areas, and the history remains with each vendor? I like to be able to go back a few years and see the dollars spent over many years.