It's definitely not possible to run multiple Steam games at once on Windows.
How is this a bad thing? I have seen others run multiple games from steam on windows at the same time. It sometimes causes a significant delay in announcing the player is in the second game that we were already playing a multiplayer match.
Steam lets you run multiple apps/games at a time, we just limit how many times you can run a single app (and that is configured on a per game basic, so some allow multiple launches).
Nothing extracted yet.
I don't have Windows any more so can't test, but in the past you couldn't run multiple games at once, I don't know if this is the case any more. But in Linux you can.
Screenshot shows me play HL2DM and CSS at the same time.
Sorry if a feature not a bug.
![screenshot from 2013-05-25 12 52 25]()