For Fiber 2.03 there are 5 python scripts that have to be place in the scripts directory. FiberGUI, Fiber2, fiber_in_menu_wizards, and init. The fiber tool can be accessed from the “Wizards” sub-menu from a Scripts window. Interestingly, the script is still working with Python 2.4. You sure you have the file in the correct folder? Probably something like “… \Blender.blender\scripts” if you are using Windows and you have a default installation. If you have a unconventional folder you can point at that by pulling down the top bar in blender and setting the path with the Python Paths variable in the File Paths area.
I can’t remember at the moment but you may need to have a full installation of Python as well. Actually I think you do need that. Get Python here http://python.org/ and learn how to configure paths here https://blenderartists.org/forum/viewtopic.php?t=7723
This should, for the most part, cover the bases. Are you on track yet?