
Cause:
Error 1721 indicates a problem with the Windows Installer package.
Solution 1
Download, unzip, and run the PreventNoahAud3Uninstall.bat file (posted in the right-hand column)
Running the PreventNoahAud3Uninstall.bat file will prevent Noahaud from being uninstalled as part of the installation of the Noah Audiogram module. The uninstall uses a script to remove the outdated Noahaud module and this script can be blocked by antivirus software.
Solution 2
Disable Antivirus software.
There have been reports of the Audiogram Module installation being blocked by anti-virus software. You will need to disable the anti-virus to allow the installation to complete.
Reports have included Trend Micro, Cylance, and Sophos antivirus packages, but may not be limited to these specifically.
A link to Cylance Support site is provided at end of Solution 1. Steps to work around in Sophos are below:
- Login to Sophos and navigate to the Dashboard
- Choose the PROTECTION Tab
- Select to Disable real-time protection

- Install the Noah 4 Audiogram Module
- Launch Noah and verify module is successfully installed
- Navigate back to PROTECTION Tab and re enable real-time protection
Link to Cylance Support site:
https://home-support.cylance.com/hc/en-us/articles/360004856873-How-To-Safelist-a-File
Solution 3
The Windows Installer program must be re-registered:
- Click Start, click Run, type MSIEXEC /UNREGISTER, and then click OK. Even if you do this correctly, it may look like nothing occurs.
- Click Start, click Run, type MSIEXEC /REGSERVER, and then click OK. Even if you do this correctly, it may look like nothing occurs, or you may briefly see an hourglass.
Try the installation of the Noah 4 Audiogram module again.