Hi Adrian
You can't edit the config file directly because Windows in its infinite wisdom makes copies of these files and likes to store them in silly places that nobody knows about.
So, here is what I suggest
First, copy your licence file to your desktop for safekeeping.
Uninstall JBP, then you will have to find the hidden files & folders and delete them.
I use Windows Vista & I can tell you where the files are, if you have winXp or other system you will have to find the eqivelent location.
Look in: C:\Users\YourUserName\AppData\Local\
Delete all folders named:- "Juke Blaster Pro" or " JBP" or "_"
Now Re-install JBP
Let Me know how you get on