Xbox controller incompatibility

[setton77]

For a reason I cannot understand, my game (steam) does not recognize my xbox360 controller input?
It maps the controls correctly in the options screen but If I try to reassign them, nothing happens "..." It doesn't take my controller's input. The game itself won't read the controller when I start it(using mouse).
I mean it isn't a huge deal. But I would like to at least TRY the game via controller?
I verified that the controller works for my other games, just not this game, I also have the microsoft accessories support exe. Although it is a windows 7 version of it and I am on windows 8.
Help?