Issue:

During installation of Autodesk software, the application is flagged as "Installed" and the Install button is grayed out, not allowing the installation to proceed.
 
User-added image

Causes:

This error occurs when a product is still recognized as installed by the system due to the presence of residual files or registry keys from previous installs.

Solution:

To workaround this issue follow these steps:
  1. Download and run the Microsoft Program Install and Uninstall Troubleshooter (also known as Microsoft Fixit). The tool will look for any remnant registry files for the product and if found, provide the option to remove these residual files for a clean installation or clean uninstall of the program.
  2. Select Uninstall.
  3. Within the utility, check to see if there is any entry related to the software which is being installed. Select it and follow the guided steps to remove it.
    • If there are several entries related to the software, utility needs to be launched at every attempt.
  4. Attempt to reinstall the Autodesk product following the Recommended installation workflow for Autodesk Products.