Open the Start menu and click on "Printers and Faxes". If you can't see it, open "Control Panel" and look for it there.

Right-click on the printer you want to configure, and select "Properties".

Choose the "Device Settings" tab, and scroll down to the bottom of this window.

Under "Installable Options," there will be a "Duplex Unit (for 2-Sided Printing)" setting. Click on "Not Installed" and change it to "Installed."

Click "OK" to accept the changes.

Right-click on the printer again, and choose "Printer Preferences" (not "Properties").

A section labeled "Print on Both Sides" should be visible. Select the edge to flip on for dual-sided printing.

Click OK to accept the settings. You're done!