New printer prints but can't add duplex feature

Question

Hi,
I have a new hp LaserJet P2055dn. After fiddling around with the preference pane I was finally able to get it to print, for some unknown reason that seems to have nothing to do with the printer driver which is located somewhere unfathomable, to me.
Anyway thereare some very understandable and clear instructions which come with the driver software but have no bearing on the panels that I find when I click on print in the preferences.
Any help would be appreciated, I'm attempting to add duplex functionality with no success,
Garrett
Here's the instructions which I cannot even begin to find in the print preference pane:
To set up a printer queue for your HP LaserJet printer:
Mac OS X:
1. Open Print Center / Printer Setup Utility.
2. Choose "Add Printer" from the Printers Menu.
3. Choose a connection type (e.g. Bonjour, AppleTalk).
4. Select the printer from the printer list.
5. Verify that correct HP Printer Model is selected.
6. Click Add to create Printer queue.
IMPORTANT – if your printer has installable options (e.g. duplex, extra paper trays, internal hard drive) you must follow these steps in order to enable these options from the print driver.
1. Select your printer queue in Print Center / Printer Setup Utility.
2. Click on Show Info.
3. Click on the pop-up menu and select Installable Options.
4. Select the control setting that correspond to the options in your printer.
5. After checking and closing this window, these options will now be available from the print dialogs.

Answer 1

I cannot say why it wouldn't do it before, I eraced and started over and am able to duplex.
Garrett