Problem with importing 3D-models from "Archive3D.net"!

[hirondelle]

Deep Exploration CAD-Edition is a seriously expensive software.

For texturing models there are much less expensive options. You could try Ultimate Unwrap for example, which can be had for around $49, or $59 for the 'pro' edition. You can even find the original freeware version of this, called Lithunwrap, if you search around the web. Both of these include model format conversion as well as UV mapping & texturing.

I would, however, recommend getting and learning Blender 2.6 for all 3D modelling-related work. It's free, and will do pretty much everything you could want, including mapping & texturing.