speech agents not available on my pc

You can also download the installers directly:

Use this link to download and install Captivate 8, TTS voices and other downloadable assets:

Adobe Captivate 8 Direct Download Links: Free Trials with no Akamai | ProDesignTools

Or follow these links directly:

Adobe Captivate comes in both 32-bit and 64-bit versions…  64-bit offers higher performance but choose the 32-bit flavor if you’re unsure what your Windows computer is.

Captivate 8.0.1 – Windows 32-bit (1.4 GB):   File 1   File 2

Captivate 8.0.1 – Windows 64-bit (1.4 GB):   File 1   File 2

Captivate 8 – Downloadable Assets – Windows (1.4 GB):   File 1

Captivate 8 – NeoSpeech Text–to-Speech Voices – Windows (1.7 GB):   32-bit or 64-bit

Captivate 8.0.1 – Mac (2.2 GB):   File 1

Captivate 8 – Downloadable Assets – Mac (1.4 GB):   File 1

Captivate 8 – NeoSpeech Text–to-Speech Voices – Mac (1.7 GB):   Voices for Mac

See the complete system requirements for Captivate 8 to make sure your computer is ready before proceeding with installation.

Hi there

It's because there are additional speech agents available (key word there) but you have to download and install them before Captivate will recognize and use them. Note the link in your screen capture.

Cheers... Rick