In order to print single-sided print jobs by default from Windows 7, click on the Start button in the lower left-hand corner of the screen and select Devices and Printers:
Right-click on the CanonMFD you are using to print single-sided print jobs and select Printing Preferences:
From the Basic Settings tab, go the 1-sided/2-sided/Booklet Printing section and select 1-sided Printing. Click OK and the default setting should be saved. Your print jobs will now print on single-sided paper.