It installed correctly this time! Thanks for your help!! If this would happen again, instead of uninstalling, what is the correct procedure to fix it?
Reinstalling surely hasn't fixed the first issue you reported, which was the program not doing anything after you inserted the serial number. That could only be caused by either the Couatl program not running (not your case), or another addon stealing the focus, which reinstalling wouldn't help.
Reinstalling was required just to fix any problems you might have caused when you removed that "KCLT file" you referred to, which I'm not sure what really way.
In general, as long as you use our Uninstaller, which is the one that runs when you uninstall from the Windows Control Panel, you should be fine. If you start moving or removing files manually, everything can happen.