Wow sorry for trying to help, I thought maybe just going over the basics first might help. Since you already know the answer to your question maybe you should try contacting Don in a private message and see if he can provide you with a registration key that will work.
Win9x Temporary Keys PRO-96 Software - Win96 - Data Management Software for the RadioShack PRO-96 and PRO-2096 Digital Trunking Scanners try reading through both of those and see if you can get a little more help in there. It also might help to upgrade to the newest version if Win96 if you don't have it already.