A practical first path is to refresh the scanner device and the Windows scanning service.
- Remove and reconnect the scanner device:
- Open Settings.
- Go to Bluetooth & devices > Printers & scanners.
- Select the affected multifunction printer/scanner and remove it.
- Disconnect the USB cable.
- Reconnect the USB device.
- In some cases, Windows 11 recognizes the scanner again after reconnection.
- If the scanner still is not detected correctly, uninstall and reinstall it from Device Manager:
- Open Device Manager.
- Find the scanner or the unknown USB device with the warning icon.
- Right-click it and select Uninstall.
- On the menu bar, select Action > Scan for hardware changes.
- This reinstalls the device driver.
- Restart the Windows Image Acquisition (WIA) service:
- Open Services.
- Find Windows Image Acquisition (WIA).
- Stop the service, then start it again.
- Restart the PC with the scanner connected if the issue continues.
- Because the error is Code 43, also check the USB connection itself:
- Try a different USB port.
- Try a different USB cable if available.
- If the device works elsewhere but not on this desktop, the port or cable can be part of the problem.
Code 43 means Windows stopped the device because the driver reported a problem. The recommended Windows resolution is to uninstall and reinstall the device. For “device descriptor request failed,” failed USB enumeration can also cause the device to appear as unknown.
References:
- Third-party drivers fail on USB IPP multifunction printers in Windows 11
- Applications are unable to find a new scanning device after another device is disconnected
- Code 43 - CM_PROB_FAILED_POST_START
- Error codes in Device Manager in Windows
- Fix USB-C problems in Windows
- Unknown USB Device (Device Descriptor Request Failed) - Microsoft Q&A
- Windows saying unknown usb device (device descriptor request failed) (Code 43) what do I do? - Microsoft Q&A