I came back from college and brought my desktop computer. Family recently switched to Verizon FIOS and got a new router because of it. Unfortunately, my connection to the new wifi network is awful, with the download speeds (tested through speedtest.net) fluctuating wildly and often dropping below 1.5 Mbps. A laptop in the same room gets 20 Mbps. I've tried a new wireless card, thinking that mine got damaged in the move home but no luck.

Here's where it gets weird: if I place the laptop near the computer, the laptop's download speeds often suffer greatly. Pulling the laptop away always fixes this. So now I'm under the impression that there's something in the computer (which I built a year ago and has had 0 issues up to this point) is causing an insane amount of wireless interference.

Also bizarre: the upload speeds seem unaffected by this problem. On the laptop and desktop, upload speeds are generally around 5 Mpbs.

Any ideas as to what could be causing this and how to test said theories would be fantastic.