Q: How to add Custom Delimited File Extensions?

A: 1) Start up Regedit, and find this value:
      (32bit) HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Jet\4.0\Engines\Text
      (64bit) HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\15.0\Access Connectivity Engine\Engines\Text
   2) Double-click the following items to add a file extension to the end of the value, like so:
      Extensions -> txt,csv,tab,asc,tsv,psv,ssv
      DisabledExtensions -> !txt,csv,tab,asc,tmp,htm,html,tsv,psv,ssv