Being able to share Steam games with close friends and family members is a great way to get more value for money out of your games, but it’s not the easiest thing in the world to configure.
You’ll need access to your own computer and your friends computer as you will have to enter your Steam username and password on both.
Never share your password with anyone.
If you don’t have physical access to your friends computer, login remotely.
On your computer
Click on Steam / Settings / Manage Steam Guard Account Security /
On your friends computer
Sign in to Steam with your own username and password.
Click on Steam / Settings / Family / Authorise this computer.
Good To Know Info:
You can share your Steam game library with up to five other accounts.
You can’t share specific games, you can only share the entire game library or nothing at all.
A game can only be played by one person at the same time. So if you want to play a game with someone else, they will need their own copy of the game.
Not all games are available for sharing
If your friend gets banned for cheating while playing one of your games, your account will also be banned. So be careful who you share with.