Re: Internet is slow and its hooked up to two computers...
If you have the modem plugged into the routers WAN port, and the other 2 eterhnet cables plugged into the ports of the router, there should be no reason (logically) that one internet would be working and one would not be.
Now below are a list of things that could be causing them to be messed up:
1. (You said you cleaned them) What did you use to clean them with? Compressed Air, Water, Windex or What. ""Cause it could be possible that you damaged one of the wires and not allowing it to get a connection or have shorted out.
2. Possiblity that one of your ports in the router has been disabled, by accident, hard reset, power surge. Also this could also mean a port on the router is damaged.
3. Have you tried switching the ports that each of your ethernet cables plug into, to make sure that one port is not bad?
Hopefully this has helped, I will keep a look on this thread to see if any updates have came that maybe I can assit you further.