You can get Windows to read text to you aloud using an accessibility tool called Narrator, which you can access from the Start menu.

If you're having trouble reading what's on your Mac's screen, here's how to get Siri to audibly read out what's on screen to you.

Enabling the first allows you to select a group of text and have Siri read that specific group back to you. Selecting the second allows you have Siri read everything that is visible on your screen.