Problems Connecting to My Computer

I am shy and new to the world of 3D printing and am willing to admit I don't exactly know what I am doing. But my computer wont recognize my printer when I plug my printer into my computer. It used to recognize it until I plugged in and out a few times in a row when I was trying to get my Repeteir to recognize my printer (which it never did). I have tried manually "adding a device" (being my printer) but my computer says"That didn't work" then it goes on to say "Try again, and make sure the device is still discoverable." I have tried restarting both my computer and printer multiple times but nothing seems to be working. Does anybody know what I might be doing wrong?

Mac or PC?