When I connect my hdd to configurable usb loader or usbloader gx it freezes, i was wondering if there has to be an iso file or a file in it for usb loaders to not freeze because it has nothing in it right now.
In short, the answer to your question is no. You just need to properly format it. I would suggest fat32. Guide HERE.
A basic introduction to Wii hacking | Brick Prevention- Things you should never do
Guide: Virtual Wii (Wii Mode) Softmod for Wii U | Guide: Softmod ANY Wii | d2x cIOS Installation Guide | How to Run & Post a System Check