How do I clear a stuck print job after trying to cancel it from system tray?

Try this:

  1. Click Start → Run
  2. Type “CMD”, then click OK
  3. Type “net stop spooler” and press enter to turn off the service
  4. Wait a couple of seconds and check the print queue from the system tray, hopefully the stuck print job has disappeared
  5. Type “net start spooler” and press enter to turn on the service again
  6. Type “exit”

Good luck!

Updated reference:
http://www.howtogeek.com/100358/how-to-cancel-or-delete-a-stuck-print-job-in-the-windows-print-queue/

If you find that print jobs remain stuck, you may need to terminate the splwow64 for 32-bit to 64-bit printer process before you can delete the stuck print job files.