- last post: 01.01.0001 12:00 AM PDT
The game is downloaded to your hard drive, but you need a good serial number to play them. Basically, you entire Valve game collection becomes one with the internet, so if your drive gets reformatted you can just reinstall Steam and redownload every Valve game you own. Also, the games automatically update now and you can use something akin to AIM in Steam to keep track of your pals and talk to them in-game.