net stop spooler
The phrase is not a standard Windows or networking command. However, in the context of "prepare paper," you are likely dealing with a printer spooler issue.
Here is what you likely need to do, broken down by what those words mean in practice: You probably want to stop the "Print Spooler" service (often referred to as the "spool" or "net spooler") so you can clear stuck print jobs before preparing paper.