USB-232/485 Not Recognized by PC After Windows 10 Update

Updated Oct 24, 2023

Reported In


  • USB-232
  • USB-485


  • Measurement & Automation Explorer (MAX)


  • NI-Serial

Operating System

  • Windows

Issue Details

I have a NI-Serial USB-232 or USB-485 device. After performing a Windows update, the system no longer recognises the USB device in Windows Device Manager or the NI-Serial Troubleshooter. LEDs do not light up on the USB device.


This issue comes about from a Windows update removing a required registry key. Versions of  NI-Serial 20.0 and before require the registry key "Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NiSerU_settings" to load the firmware for the USB-232/USB-485.
When Windows performs an update, it determines this key to be stale and deletes this key.

To solve this, export a working "Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NiSerU_settings" key and import this into the Windows Registry Editor. There is a key with the default installation path attached at the bottom of this article.

Note: NI takes no responsibility for importing Windows Registry keys into your system. 
To import the Registry Key into Windows Registry Editor:
  1. Download "Serial.reg" or export the registry key from a working system
  2. In the Windows search bar, type "Regedit" and press enter.
  3. Go to File -> Import -> select "Serial.reg"
  4. If required, unplug the USB-Serial device and insert it again. (A computer restart may also be necessary).

If you cannot import the registry key, please follow the article: Force Reinstall Non-Working or Corrupt NI Software and reinstall the NI-Serial driver to recreate this registry key.

Additional Information

NI-Serial Version 21.3 removed the requirement for this registry key to function.