The module makes use of cron jobs.
Unpack in your modules folder (usually /sites/all/modules/) and enable under Administer > Site Building > Modules.
Here are some key features of "Link 404 checker":
· Queries all links for a status code
· Stores the status code of the links (200, 352, 404, etc. )
· Runs in batches per link field. For example you can tell it to only check 2 links per link field during a single cron run.
· Can unpublish/put-in-moderation queue nodes with links resulting in 404 errors.
· Drupal 5.x
· Drupal Link module
· Drupal Content Construction Kit module