Having a hard time finding out exactly what system .sfc is supposed to translate to. Apparently everybody knows, so there's nowhere you can find out.

But it shouldn't matter, because I've tried them with Nestopia, FCEUX, Bsnes AND SNES9x (I THINK they're Super Famicom and/or SNES roms. I know they're old.) I know the problem's not the .sfc files themselves, because I've tried a bunch of different ones (and also tried without unzipping them). I know it's not the emulators (unless I'm still somehow not using the right one). The .sfc files will not show up in the open/browse option, and if I try to open them with a specific emulator, it says 'error loading rom' or some variation.

WHAT IS HAPPENING?
Edit: Oh, and I'm using windows 7 64 bit, if that makes a difference.