Hi nathalym,
Have you tried restarting the computer as well? I would like you to follow the steps listed below to forcefully clear your print queus:
1. Go to Start, Control Panel and Administrative Tools. Double click on Services icon.
2. Scroll down to thePrint Spoolerservice and right click on it and select Stop. In order to do this, you need to be logged in as Administrator. At this point, no one will be able to print anything on any of the printers that are being hosted on this server.
3. Next you need to go to the following directory: C:\WINDOWS\System32\spool\PRINTERS. Delete all the files in this folder. This will clear all print queues (it’s a good idea to first make sure there are noother print jobs being processed on any of the other printers on the server because doing this step will delete those jobs also).
4. Now you can go back to the Services console and right-click and choose Start for the Print Spooler service.
I hope you found this helpful, please let me know if this was successful.
I found this great information from http://www.online-tech-tips.com
Thanks,