Enabling back an input filter that has been disabled in Drupal 7

How to enable a previously disabled input filter in Home » Administration » Configuration » Content authoring?
This was also one of my questions when I wanted to enable back the Filtered HTML input format but I noticed that I could not see it anymore on the Text Formats page from Home » Administration » Configuration » Content authoring.
One solution is to open you database and go to the filter_format table where you will find all the filters available to your Drupal installation. This table has a status field which needs to be set to 1 in order to enable the filter. Find your filter in this table and enable it!