Wired, but through the wifi router.

I think this all has to do with something else. When I bought this PC, I was told that it did not have an onboard ethernet connection. I've always just used a USB wireless plug-in with a little antenna. My wife recently broke it off. I put it back together, but it doesn't work any more (I've broken it and put it back together before). So I just ran an ethernet cable directly from the wifi router into the PC and have internet now, but it is painfully slow. Just a few minutes ago I ran the cord directly from the new modem into the PC just to test it out, but it won't connect to the internet that way.