Install Google Hangouts Plugin. Go to Google Plus hangouts and click Start a Hangout, the red button in the top right. If this is the first time you've used a Hangout, you'll be prompted to install the plugin to your computer. This is a one-time install, so once it's done, it's done.How can I use Hangouts On my PC?
How to make voice calls on your computer using Google Hangouts Go to Google Hangouts. Select the telephone icon with the words "Phone Call" under it from the front page. A window will appear on the right side of the screen. Your call will be initiated.