- Visit: https://fonts.google.com/specimen/Open+Sans
- Click Select the font
- Click on the hidden popup where it says 1 Family Selected
- Click on the download icon to download the selected font
- Open/Extract the downloaded .zip file
- Highlight all the Open Sans files in the extracted folder
- Double click/Open them
- Click install
- Quit PowerPoint and Re-open
- Open Sans should now be shown