How to delete records where Primary Key is NULL?

[#1]

I somehow have some entries in my schema where PK Attribute is NULL.

I created the workflow by querying those rows and added Delete Data Step.. but records wont get deleted.. Error message is PK cant be NULL.                

[#2]

Please post the name of the program you use so a Moderator may move this message to that forum

-A program would be Photoshop or Dreamweaver or Muse or Premiere Pro or ???