Hello,
If you are using an HP LaserJet P2055dn, the printer supports automatic two-sided printing. If the duplex option keeps reverting to "Not Installed", the first thing to check is the printer driver's automatic configuration.
HP documents the following troubleshooting procedure:
Open Control Panel → Devices and Printers.
Right-click the HP printer and select Printer properties.
Open the Device Settings tab.
Under Installable Options, find Automatic Configuration.
If Update Now is available, select it and click Apply. Allow the driver to retrieve the printer's configuration.
If duplex is still not detected, set Duplex Unit (for 2-Sided Printing) to Installed manually and click Apply.
Open Printing preferences and enable automatic two-sided printing as the default.
Close and reopen the application, then test a multi-page document.
HP notes that when automatic configuration fails, the duplex unit may default to "Not Installed".
If the setting reverts again, please check the driver name under Printer properties → Advanced, and whether the printer uses a USB, WSD, Standard TCP/IP or shared connection.
For an HP Universal Print Driver installation, HP provides specific guidance for correcting duplex detection.
I would avoid removing the printer or changing network-port settings until the driver and connection type have been identified.
Official references:
HP — Unable to auto-duplex after installing the Universal Print Driver: https://support.hp.com/za-en/document/c06453868
Microsoft — Autoconfiguration During Device Installation: https://learn.microsoft.com/en-us/windows-hardware/drivers/print/autoconfiguration-during-device-installation
If possible, please also confirm the Windows version and whether the "Not Installed" setting returns immediately after reopening Printer properties or only after restarting Windows.
Disclosure: Prepared with AI assistance and checked against official HP and Microsoft documentation. The issue has not been reproduced on the affected printer.
NIKOLA KUBERA