@Kimberly,
The file is actually a zip file. Just rename the extension from .3 to .zip and it will open with your zip utility. Inside the zip file you will find the actual program.
As a side note, I am looking into DOS Commands suggested because Spekan is doing something weird to the Pro/E installation. Now every time Pro/E launches, it says it can't find the start up program called "Spekan". I can't stand it when software does something I don't want it to do or understand what changes it's making. I am going to try and create my own batch script to handle the simple renaming I want. Just an FYI.
"Too many people walk around like Clark Kent, because they don't realize they can Fly like Superman"