Corrected entry: During the entire fight scene in the hallway of Hammer Industries, Natasha Romanoff only has a pistol on her left hip. None of the guards she takes out have guns, but when she busts into Vanko's room, she is holding two pistols.
Friso94
13th Feb 2013
Correction: Incorrect. Natasha carries a Walter PPK/S on her hip while entering the building. The guards shown have holstered H&K USP compact pistols. Considering how many she beat up to get there, it is conceivable that she stopped to grab a USP out of an unconscious guard's holster before breaching the control room with her PPK as well as the guard's USP.