Enable Print Job Notification Messages
By default Windows notifies a user with a popup message that their print job has been completed on the printer. This setting controls that behavior.
Open your registry and find the key below.
Create a new DWORD value, or modify the existing value, named "NetPopup" and set it to equal "0" to disable notification or "1" to enable it.
Restart the printer spooler service or restart Windows for the change to take effect.
Settings:
System Key: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Providers]
Name: NetPopup
Type: REG_DWORD (DWORD Value)
Value: (0 = disabled, 1 = enabled)