Clear the print queue in Windows 8 by going to the Devices and Printers tab in the Control Panel. Right-click on the printer, select See What's Printing, and click File, and then Cancel All Documents to clear the print queue.
The print queue can also be cleared in Windows 8 with the Command Prompt. Run the Command Prompt as an Administrator, and stop the spooler service by typing "Net Stop Spooler", without quotes. Follow this up with "del %systemroot%\System32\spool\printers\* /Q", again without quotes. This clears the print queue. Start the spooler again with the command, "Net Start Spooler" without quotes.
If print jobs are still in the queue even after canceling all documents, simply restart the computer.