Microsoft Speech Platform Voices
Required software
Microsoft Speech Platform Runtime is required for most voices to function. Running on installers without this will throw an error that you don't have a runtime installed. However, the voices do not appear in the SAPI5 list, because they are fundamentally different technology, as they are exclusive for some third-party text-to-speech readers.
Voices
Voices that came from the Microsoft website, low quality Helia not included to prevent conflicts.