Every engineer is waiting for the day when we can have 2 parts open on separate screens inside SolidWorks. With SolidWorks 2012 that day has arrived. Solidworks has some new workspace option found under View, Workspace. Part of this increased functionality allows a user to tile their parts on screen so you can view 2 parts on the same screen. So to get parts on separate screens, you can set solidworks to span across both screens, and then by tiling your windows you end up with 2 parts on 2 screens. Give it a try.