Sometimes, users will have issues with their print jobs. If this happens on a printer shared on a server, they will block rest of the users. A quick and simple fix is to stop the Print Spooler, delete the jobs and restart the service back.

net stop spooler
del /Q /F /S "%systemroot%\System32\Spool\Printers\*.*"
net start spooler

This does the job nicely.