To watch Amazon Prime on your computer, you will need to first install the Chrome web browser. Once installed, open the Chrome browser and click on the three lines in the top left corner of the browser window. In the "nearby" tab, select the "Add a site…" option. Type chromecast.com into the search bar at the top of the page and press Enter. Scroll down until you see "Chromecast" listed next to a blue button with an arrow pointing left. Click on Chromecast and follow the instructions on-screen to install it. After Chromecast is installed, open up a new tab in your Chrome browser and go to https://www.amazon.com/. On the Amazon home page, click on "TV Shows & Movies" and then select "Amazon Prime Video." If you are using a laptop, click on "Video on Demand." If you are using a mobile device or an Amazon Echo Show, click on "Movies & TV."