[support] file type not present in field type dropdown

Hello all, I am using Drupal 7.10 with mix_and_match theme. In content types/manage fields, I am trying to create a field of type 'file'. In Drupal 7, this type is supported by default. But I don't get file type in the field type dropdown box. What could be the reason? Thanks in advance http://drupal.org/node/1462092 Regards, Raghava.