Clearing External IDs

 
In some situations, you may want to clear all imported External IDs that are associated with certain tasks.  This is especially useful when you want to perform one-time imports from different MS Project files.  MS Project does not have a way to identify activities uniquely when using multiple files, so you must purge the previously imported activity IDs before importing tasks from another MS project file.
 
Before using this tool, make sure that the tasks for which you wish to reset the External IDs are visible.  Click on "Clear External IDs for Visible Tasks" menu.
 
 
Follow the instructions in the wizard to clear the IDs.