Delete all files in this folder to remove any corrupted installation scraps.
Sometimes, the "Port Monitor" is flagged as a security risk by 3rd party antivirus software (McAfee, Norton, etc.) because it interacts deeply with the system ports. could not install canon mf port monitor
When the installer fails to set this up, your printer might appear in "Devices and Printers" but remain offline or unresponsive. Delete all files in this folder to remove
Alternatively, look for a program named CNMNPU.EXE on your installation media; this specifically deletes problematic Canon ports that may be causing the conflict. Open Settings > Apps > Advanced app settings . Alternatively, look for a program named CNMNPU
Windows manages all print jobs and ports through the Print Spooler service. If this service is "holding" a port, the Canon installer will fail. Press Windows Key + R , type , and hit Enter. Find Print Spooler in the list. Right-click it and select Stop .