USB Device Missing in NI-MAX but Is Present in Windows Device Manager

Updated Nov 14, 2018

Reported In


  • Measurement and Automation Explorer (MAX)
  • LabVIEW



Issue Details

I can't see my USB Instrument listed in Measurement & Automation Explorer, but it is present as a USB Instrument in Windows Device Manager.  Why am I seeing this behavior and how can I fix it so I can communicate with my instrument?


  • Check if you have NI-VISA driver installed on your computer. If not, visit the VISA downloads page on and download and install your appropriate driver.
    • Make sure to restart your computer after installing
  • Try resetting the NI-MAX database, as detailed in the article How to Fix or Reset the NI MAX Database File.
  • If you have worked with third-party VISA devices on the same machine, you may need to set NI-VISA as the primary VISA implementation, as detailed in the article After Installing 3rd Party VISA Software NI VISA No Longer Works.
  • If VISA is installed, try reassociating the USB device to use the NI VISA driver:
    1. Go to Windows Device Manager
    2. Right click on the device and select Properties
  1. Select Update Driver option on the Driver Tab
  1. Select Search automatically for updated driver software, and then check to see if MAX can see your device. If MAX still cannot see your device, repeat steps 1-3 and then proceed to step 5.
  1. Select Browse for File and navigate to C:\WINDOWS\System32\drivers\ausbtmc.sys or C:\Program Files\IVI Foundation\VISA\IVI USB Staging\i386\ausbtmc.sys
    • Depending on your processor architecture, the folder named i386 may be named differently. The second file path may contain \b841aa80\windows\ inbetween the IVI USB Staging and processor folders
  1. Select Next and Finish to complete the driver update
  2. Go to MAX and refresh the window to look for the USB device.
    • In case that the previous steps does not work, try to uninstall the driver on Windows Device Manager, restart the computer and reassociating the USB device following the above steps.

    Additional Information

    If the device shows up in Device Manager, it means that the Windows Machine recognizes the USB device and has associated a specific driver to communicate with the device. One possible reason this instrument doesn't show up in MAX is that Windows isn't associating the correct driver with the device. Some vendors include a specific device driver for their instrument, so when Windows sees that particular instrument it associates that vendor specific driver with the instrument. MAX however, uses the ausbtmc.sys driver to communicate with USB devices. 


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