Detection of External Monitor

Question

Notwithstanding use of a brand new USB-C to DisplayPort cable, my laptop is not detecting my HP external monitor

Answer 1

A new cable does not guarantee compatibility. The laptop’s USB-C port must support DisplayPort Alt Mode, Thunderbolt, or USB4 video output. Some USB-C ports support only charging and data.

Try every USB-C port on the laptop. Look for a DisplayPort, Thunderbolt, or lightning-bolt symbol beside the port.

Please type msinfo32.exe in the search on the taskbar and hit enter, then share a screenshot of the pop up.

Answer 2

Try these steps in order, testing the monitor after each step:

1. Confirm Windows is set to use an external display
   • Press Windows logo key + P.
   • Select Extend (or Duplicate) instead of PC screen only.
2. Basic hardware checks
   • Disconnect all accessories from the laptop (docks, hubs, other adapters) so only the USB‑C → DisplayPort cable and monitor are connected.
   • Make sure the USB‑C connector is fully seated in the laptop and the DisplayPort end is fully seated in the monitor.
   • Try a different DisplayPort input on the HP monitor (if available).
   • Test the HP monitor with another PC using the same cable if possible, or test with a different cable. If another cable works, the original cable is faulty even if it is new.
3. Try other video outputs (if the laptop has them)
   • If the laptop has HDMI, VGA, DVI, or another DisplayPort, connect the HP monitor using one of those ports instead of USB‑C. This helps determine whether the issue is with the USB‑C port or with the monitor/cable.
4. Reset the graphics driver
   • Press Windows logo key + Ctrl + Shift + B. The screen may blink and a beep may sound; this resets the graphics driver and can force Windows to detect the monitor again.
5. Restart the device
   • Select Start > Power > Restart.
   • If that does not help, select Start > Power > Shut down, wait a few seconds, then power the laptop back on and reconnect the monitor.
6. Check and refresh the display driver
   • Open Device Manager (type device manager in the taskbar search and select it).
   • Expand Display adapters and note the adapter name.
   • Right‑click the adapter, select Properties > Driver:
     • If the problem started after an update and Roll Back Driver is available, select Roll Back Driver and follow the prompts.
   • If roll back is not available or does not help:
     • In Device Manager, right‑click the display adapter and select Uninstall device.
     • Check Attempt to remove the driver for this device, then select Uninstall.
     • Restart the PC.
     • Open Device Manager again, right‑click the display adapter, and select Update driver > Search automatically for updated driver software and complete the wizard.
7. If still not detected
   • Open Settings > System > Display and use the Detect button (if available) to force Windows to look for another display.
   • If none of the above steps work, use Feedback Hub in Windows to file a bug, including details of the laptop model, HP monitor model, and that it is connected via USB‑C to DisplayPort.

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References:

• Troubleshoot external monitor connections in Windows
• Docking station external monitors not working when a Windows 10 version 1703-based portable computer is connected
• how to update display drivers - Microsoft Q&A