Sometimes the Quicktime installer is unable to add the Quicktime file-path to the systems Path variable.

In these cases, Isadora will say that Quicktime needs to be installed even though it is installed and working.

To correct this issue, the file-path (if installed in default location) C:\Program Files (x86)\QuickTime\QTSystem\

needs to be added to either the Systems Path variable or the Users Path variable.
The editor is located at: Control Panel\System and Security\System\  then, Advanced system settings\Enviroment Variables

If admin rights are available, adding it to the System variables Path is best.

But if the user has limited rights, it should work added to the Users Path variable.

It may require login out and back in to be refreshed.

The path can be checked from the command prompt by typing, path, and then enter

This will list all paths set. Ensure the Quicktime path is listed.