Once the print job is created, it's managed by Windows and your print server (if any).  It no longer has anything to do with Lacerte.

Open your the print queue of the printer the job is on and delete it from there.  Sometimes, it could be locked up and you may not be able to delete the job.  In those cases, restart the printer before trying again.  If that still doesn't work, restart your computer before trying to delete the job.

In case you use a print server and you can't delete the job from the PC, you may need to delete the job as the administrator on the print server.