To set up your Oculus Rift S or Rift, you'll need to download the Oculus app on your PC. Before you install the Oculus app, check to make sure that your hard drive has at least 4GB of free disk space.
When you install the Oculus app on your computer, it'll install on the C: drive. If you want to install the app on a different system drive follow this support article for additional instruction.
To download and install the Oculus app on your computer: