1. Create a query of all pledges.
    1. Navigate to Query and choose to create a new Gift query.
    2. Select the following Criteria:
      1. Gift Information > Gift Type equals Pledge (or Gift Type is one of Pledge, MG Pledge)
    3. Save and close query.
  2. Run the Written-Off Report and on the General tab of the report, mark "Create Gift output query."
  3. Preview the report and save the output query when prompted. 
  4. Merge the queries using Sub as the merge operator.  The output query from the pledge query will be used as the secondary query to find all pledges that do not have write offs.
For assistance or more information on creating or merging queries, please reference How do I create a query in Raiser's Edge (includes video demo) and How to merge queries