If you have jobs pending and your Spooler is started, you may have a corrupt print job.
If you receive no error messages, this is most likely the cause.
To fix the problem:
1. Use Control Panel / Services / Spooler / Stop.
2. Delete the files in your Spool folder. The default location is %SystemRoot%\System32\Spool.
3. Use Control Panel / Services / Spooler / Start.
4. Reprint the lost jobs.