HP Color LaserJet Pro M252dw password/pin needed to fix auto-duplex?

[ericTreeLight]

The printer had to be reinstalled. Windows 11 "Add Device" found it, and added it.
It was then printing to A4 paper instead of US Letter. Okay. Easily fixed.

It was also missing the color option, at one point. I followed a procedure to fix
that (no longer recall the details, not knowing I would need them...)

The printer is now working, but for some reason auto-duplex is no longer available as a setting.
Only options were one-sided or manual duplex (ugh).

I found an "HP Print Doctor" download that is supposed to cover the case where
auto-duplex suddenly fails.

But I when I try to run it, it wants the printer password.
Questions:
   1) Who in the heck remembers a printer password, many years later?
        (I keep a record of many details, but who knew this would be needed.)

   2) The printer is not on WiFi. It's directly connected via USB.
        So unless I was forced to set one, I chose the default. What might that be?

  3) Do I really have to get some kind soul to give me a private reset-bot
      of some kind, so I can run the downloaded "doctor", in hopes it willl
      make auto-duplex come back?

   4) Is there some other way to restore auto-duplex??

[Repairatrooper]

You should be able to fix the duplex issue without a password. On your computer go to control panel, then right click on devices and printers and select open from the drop down menu. Then right click on the icon for your printer and select "printer properties". Click on the advanced tab and make sure you have an HP driver installed and not a Microsoft IPP driver. If it shows and IPP driver, delete the setup, download the correct HP driver and reinstall. If it show an HP driver, then click on device settings and scroll down until you see duplex option  and make sure it is set to "installed". 

if you need to clear a password, check YouTube as there are many videos posted there on how to reset. 

[ericTreeLight · Accepted solution]

STEP 1: Default password is 1234. (My printer is USB-connected to computer, so I don't care who knows it.)

STEP 2: Download the drivers from HP (don't depend on MS.)
STEP 3: Run the installer HP downloaded. (It asks you to deinstall the current drivers.)

STEP 4. As it asks, reboot to finish deleting the drivers.

STEP 5. Run the installer again to install the new drivers.

STEP 6: Revel in the joy that is a working printer
               When you go to Printer Preferences, you now see 2-page printing options flip long edge or short edge
                as opposed to the previous options: Duplex (manual) long edge or short edge.