I am new to using FSXWX but I don't have a registered version of FSUIPC I like the free version better but I guess that means I can't use your WX program them
As a matter of fact, you can use FSXWX nonetheless!
The only difference that it makes are the not available wind smoothing options within FSUIPC. Although I do recommend to use them with the registered version you probably won't see any difference without them.
So, just try. It's free anyway!
Regards
FSXWX is the only WX weather program I use now