Canon S820 User Manual page 161

If the WPS driver or CAPT driver is installed, either uninstall it or change the driver
port to FILE as follows.
The WPS (Windows Printing System) driver or CAPT (Canon Advanced Printing
Technology) driver may disrupt normal printing.
1
Click the Start button, then click Settings and Printers.
For Windows XP, click Start and select Settings, Control Panel, and then
Printers.
2
Display the WPS or CAPT driver properties, and click the Details tab.
3
Change the Print to the following port field to FILE.
Troubleshooting
Problems Unique to Windows 161