did the following steps now disk is not recognized!
You could be experiencing a hardware issue.  It could be a problem with your hd enclosure.  But, let's try this. Maybe the format didn't take and you still have the disk formatted for NTFS.  In terminal, run:

 diskutil list


Run this command before and after you attempt to format the drive. Post back the before and after lists.

Do you want to share with Windows?  For now, let's set it up for the mac. I suggest going with the most common setup for an external disk.