Steam is a great client for managing your PC games, but it pauses all downloads whenever you're playing a game by default. Fortunately, you can get around this.
Once you start a game, all of your downloads will immediately pause. It's a pain because playing a game is the best way to kill time while waiting for another game to download. Luckily, you can force Steam to download games while you play. Just fire up the game you want to play, then follow these steps:
- Press Alt-Tab to get back to the desktop, then pull up the Steam window.
- Hover over "Library" and select "Downloads".
- Click the big "Resume All" button, as seen in the screenshot above.
Your downloads will begin immediately. Keep in mind that if you're playing an online or multiplayer game, downloads might affect your ping, but singleplayer games should be fine. Remember, you can also limit your download speed if you want to minimise that effect.