Okay, I'll explain a little differently.
I don't know how this folder-lock works, but I'm assuming it encrypts the folder into a format which is readable only by the folder-lock software. If you then plug this into a computer that doesn't have folder-lock installed, it will show up as an unknown file type. You won't be able to read the contents (or makes sense of them, because it is encrypted) but you also won't be able to open it because there is no software associated with that file type. You will have to install folder lock on the PC to recognise the file, then you'll be prompted for the password.