Serial Device Has No Driver Associated in MAX

Updated Jan 19, 2023

Reported In


  • USB-485/4
  • USB-485/2
  • USB-485


  • NI-Serial

Issue Details

I have a USB Serial device, such as a USB 485/4, and I've installed the NI VISA and NI Serial drivers. My device shows up in MAX (measurement & Automation Explorer) but reports that "Windows has no driver associated with this device" and I can't use the device. How do I fix this?


This can be caused by the serial device trying to use a COM port that's already used by a different device on your machine. To fix this, change your COM port assignments so there aren't any conflicts. You can change the COM port of the NI Serial device by consulting this article , or you can change the COM port of the non-NI device:
  1. Right-click on the COM device entry in Windows Device Manager
  2. Select Properties
  3. Go to the Port Settings tab and click Advanced...
  4. Change the COM Port Number drop-down entry at the bottom of the Advanced Settings pop-up
If you try and change the COM port of the conflicting NI device using this Windows method, it won't work and you'll receive the error There was an error renaming the COM port. The IOCTL call failed.​ You must use the NI Serial tool to change the NI device's COM port.

Additional Information

It's also possible for unused or not-present devices to still be occupying COM ports on your machine.