External hard drive is supposed to pick up connection to computer wirelessly. what am I doing wrong?

Huh? Why is the hard drive plugged into the modem? You might plug a HD into a router, but never into a modem. THe modem doesn’t have the disk management software.

You need to be more informative here. WHAT hard drive, and what modem/router/computer do you have?

Well, the dudes at the Apple Store sold me a cord that goes from the hard drive, which has a big silver apple on the top (it’s white and square, if that helps identify it, and no, I don’t have any paperwork) and told me to plug the other end into the modem. Modem has a place where said cord plugs in, whereas my router does not. I should go see them again, right?

Not that I know much about this, but are you sure that the white thing with the silver apple on it is not a router? Cute white box with apple logo

Its twin.