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

Updated Sep 14, 2021

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. NI-Serial requires 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.

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

There have been various reports about glitches or issues after updating Windows 10. 
Some of the issues were reported as known or resolved issues on the Microsoft Known Issues Pages.