Select an (it defaults to your main drive, but you can change this).
: When you first launch Steam, it will automatically download and install essential updates to ensure you have the latest version of the client. Sign In or Register : Existing Users : Log in with your username and password. Steam Software Download
If you encounter issues such as a "Disk Write Error" during your first game download, you can try: Select an (it defaults to your main drive,
: Use the Steam Support guide to clear your download cache. Steam Software Download