Printer Port is used by another device

Just only check and delete error print task queue in all of printers.

Start->settings->printers and faxes.

Right click and open each printer on your machine to find which printer remain error queue and delete it.

Good luck...

sUPERTUYZ

Found this in the manual on canon website if it is any help.
What to Do if a Printer is Not Operating Correctly The scanner uses the standard Windows parallel port driver for scanning and printing operations. As a result, connecting printers that employ their own parallel port drivers, such as Epson inkjet printers, to the scanner’s printer port will cause the scanner or printer to malfunction. Such printers must be handled as follows: • Contact the manufacturer to find out whether or not your printer uses the standard Windows parallel port driver.
Using Epson Printers (Windows 95/98) It is advisable to adjust the Spool Manager settings as follows to avoid mis-operation of the scanner during printing.
How to Adjust the Spool Manager Settings 1. Click the [Start] button on the Windows taskbar and select [Programs], [Epson] and [Spool Manager]. 2. Double click the icon of the printer currently in use. 3. Click to place a checkmark beside the [Use Print Manager for this port] option in the settings dialog. 38 N340P/N640P Getting Started • Selecting the [Use Print Manager for this port] setting causes the computer to spool all of the print data onto the hard drive before sending it to the printer, resulting in a printing speed that is moderately slower than if this setting is not selected. Use of the Epson Printer Window software that accompanies Epson printers may cause the scanner’s scan speed to drop dramatically, failure of the scanner to be recognized by the computer and incorrect operation of CanoCraft CS-P. If you experience problems, please try to solve them by following the procedures below to disable the Epson Printer Window. How to Disable the Epson Printer Window 1. Click the [Start] button on the Windows taskbar and select [Programs] and [Windows Explorer]. 2. Use Windows Explorer to navigate to the [Windows], [Start Menu], [Programs], and [StartUp] folders and delete the [Epson Printer Window] icon. • Deleting the Epson Printer Window software will disable the capacity to confirm ink levels and read error messages for the printer. How to Solve Problems with Other Printers That Are Operating Incorrectly Begin by turning off the printer’s bi-directional functions (in its status monitor or control panel). Please refer to the instructions that accompanied your printer for an explanation of this operation. If this does not solve the problem, connect the printer directly to the computer’s parallel port and alternate with the scanner as required.

You could try uninstalling the scanner and the printer, and reinstalling them. Try installing the scanner first. Another thing you can try is to buy a new parallel port card. Good luck