Purpose
You want to know what MSI Error 1605 means and how to work around it.
Resolution
This error is returned when you attempted to uninstall an application that isn't actually installed on a target system. Error 1605 is a Windows error which means "ERROR_UNKNOWN_PRODUCT". Below is a screenshot from PDQ Deploy Enterprise mode where a command is configured to uninstall Adobe Reader. Notice that you can add 1605 to the Successful Return Codes field so that the deployment won't return an error if the Adobe Reader doesn't exist.
This can sometimes happen if the version you are attempting to uninstall is not present on the system. In these cases, if you don't know what version is installed, or you don't know if the application is even installed, you can use another method to uninstall by name.
