Quick fix: Open Settings → Bluetooth & devices → Printers & scanners → (your printer) → Printer properties → Device Settings tab and confirm Duplex Unit is set to Installed. Most printers ship with this set to Not Installed by default, which hides the duplex option from print dialogs.

Your printer supports two-sided printing (duplex) — the spec sheet says so, the box mentions it, the hardware has the duplex unit visibly inside. But Microsoft Word, Edge, and other apps show no two-sided printing option in their print dialogs. The fix is in Windows’ printer-property accessory configuration: the duplex unit needs to be marked Installed before apps see the option.

Symptom: Two-sided / duplex printing option doesn’t appear in print dialogs despite the printer supporting it.
Affects: Windows 11 (and Windows 10) with duplex-capable printers.
Fix time: ~5 minutes.

What causes this

Printer drivers expose features based on installed accessories. The duplex unit is an “optional” accessory from the driver’s perspective — even if it ships with the printer, the driver doesn’t auto-detect it on first install. The Device Settings tab in printer properties lists each accessory with an Installed/Not Installed dropdown. By default, duplex is often Not Installed; switching it to Installed makes the duplex option appear in print dialogs.

Method 1: Mark the duplex unit as Installed

The standard fix. Works for most network and USB printers.

Open Settings → Bluetooth & devices → Printers & scanners.
Click your printer.
Click Printer properties.
Switch to the Device Settings tab (sometimes labeled Device Options or Optional features).
Find Duplex Unit (may be named Duplexer, Auto-Duplex, or Two-sided print accessory).
Set to Installed from the dropdown.
Click Apply → OK.
Open any app and print. The print dialog should now show a Print on both sides option (or similar wording).

If Device Settings tab doesn’t exist or doesn’t have a Duplex entry, your driver doesn’t expose accessories this way — proceed to Method 2.

Method 2: Reinstall the OEM printer driver

Use when the basic Microsoft generic driver is installed and doesn’t expose duplex.

Identify your printer’s driver provider. Settings → Bluetooth & devices → Printers & scanners → (your printer) → Printer properties. Switch to the Advanced tab. The Driver field shows the driver name.
If it’s a generic driver like “Microsoft Print to PDF” or “Microsoft IPP Class Driver,” install the manufacturer’s specific driver.
Visit the printer manufacturer’s support page (HP, Brother, Canon, Epson). Search your model.
Download the “Full Feature Software and Drivers” package (often hundreds of MB but includes all accessories).
Uninstall the current driver first: Printer properties → Advanced tab → New Driver (later), then in Settings → Apps → Installed apps, uninstall any existing manufacturer software.
Run the OEM installer. Choose Network or USB based on connection.
After install, recheck the Device Settings tab — duplex should be auto-detected or available to install.

Microsoft’s generic IPP driver supports duplex but doesn’t always auto-detect it. The OEM driver typically does.

Method 3: Print with duplex via PowerShell as a workaround

Use when the GUI still doesn’t show duplex but the printer hardware supports it.

Open Terminal (Admin).

Check the printer’s capabilities:

Get-PrintConfiguration -PrinterName "HP LaserJet" | Format-List DuplexingMode, Color, PaperSize

Set duplex mode for that printer:
```
Set-PrintConfiguration -PrinterName "HP LaserJet" -DuplexingMode TwoSidedLongEdge
```
Options: OneSided, TwoSidedLongEdge (portrait flip), TwoSidedShortEdge (landscape flip).
Now any print job from any app will use duplex by default.
To verify: print a test page. Confirm the output is double-sided.
To toggle off: Set-PrintConfiguration -PrinterName "HP LaserJet" -DuplexingMode OneSided.

This bypasses the dialog and forces duplex at the print system level.

How to verify the fix worked

Open Word, Edge, or any app and print. The print dialog shows a Print on both sides option.
Select duplex and print a multi-page document. Output is double-sided.
Run Get-PrintConfiguration -PrinterName "HP LaserJet" | Select DuplexingMode in PowerShell. Returns TwoSidedLongEdge (or similar).

If none of these work

If duplex remains hidden, three causes apply. Printer doesn’t actually have a duplex unit: budget models sometimes share the same model number as duplex-capable variants but without the duplex hardware. Check the printer’s actual model number against the manufacturer’s spec sheet — “dn” suffix usually means duplex + network. Driver version too old: very old drivers may not expose duplex. Use the manufacturer’s latest universal print driver. Universal Print Driver limitations: HP UPD, Xerox Global Print Driver, and similar “works on any model” drivers sometimes don’t auto-configure accessories — use the model-specific driver. For chronic missing duplex on duplex-capable hardware, the manual duplex workflow (print odd pages, flip stack, print even pages) is the fallback for one-off documents.

Bottom line: Missing duplex option is almost always the “Duplex Unit: Not Installed” accessory setting — change it to Installed in Printer properties, and the option appears in every print dialog.