Not really. The only company that has a true - and decent viewer for 2D/3D CAD files is Vectorworks, but it's specific to their application files.
You'll have better luck with DXF file viewers; if you don't know what a DXF file is then you should search the web a bit or talk with the creator of the file - and ask why in the heck you don't have a DXF file. Naming the application that generated the file(s) would be helpful as well - offering "dwg file" really means little, this coming from an AutoCAD user for over 25 years...
Also, you're best "viewer" for 2D/3D is likely going to be web-based. Look into AutoCAD 360 or Microspot.