Without any information of what you did, how do you want us to help you? oh wait..
Are other USBLoader/GameCube backup Launcher recognizing them?
It could be because you didn't to anything at all, because you don't know what to do, in that case what you need is a tutorial.
It could be because you did everything but it's still not working, in that case you need to explain what you did, what's the problem, where it happens, etc.
Please give more precisions, like:
Where did you put the games (SD, USB, folder name), which format (iso, fst, gcm, filename), which version/revision of the loader, which option did you use in the loader, which GC loader/version (DIOS MIOS or Devolution?), etc.