So what's the problem actually?
The question was not whenever there was a problem or not but whenever or not there was a mandatory activation for every install.
You can call it activation or "download completion check", it doesn't matter from user's perspective in a slightest way and doesn't affect him...
And there was a big deal discussion with "your games have to be activated before you play, omg it's so terrible!" I could never understand.
Steam automatically install the game during the download, I fail to see how you actually manage to "install" it afterwards. We are talking about Steam not Gamergates,
omg... if you actually bothered to read any posts in this thread, you'd know that I'm talking about mandatory DirectX , .NET and other installations before first game launch, because people said you have to do all that while being online (and that you have to run game at least once in online mode to go to offline mode for that game) which is simply not true.