How do you use a downloaded interface that it is on the interface menu in Soldat but you are not registered? Because everytime i try to use the Halo XP interface it says You Must be registered to access this mod or something like that. And i got scammed last time i payed for a registration and MM nvr emialed me back!

Register.
I seriously doubt he would rip you off, so chances are you didn't use an official registration website. I registered just fine.

And next time, please post this in the help section.

to use those you need to register but if your asking about how to get a non registered one that you downloaded i can tell you