So... comcast NEEDED to change out my gateway, which, before was ok.

So right after the man leaves I get on my pc, and, here's what happens.

There's a 2.4 ghz and a 5ghx connection


The 2.4 ghz connection is painfully slow but has 5 bars

The 5ghz connection is a lot better but has 4 bars


Downloading things are not possible
Uploading is impossible

But my ping is fine, great, in fact.

When I am playing a game, no lag, it's fine, but if I wanted to download a movie, forget about it.


I want to use ethernet with my PC but it's downstairs and my router MUST BE upstairs. I'd need a 20 foot long ethernet cord.

Speed test for 2.4: http://www.speedtest.net/my-result/5179724083


Speed test for 5ghz
http://www.speedtest.net/my-result/5179731715
 
Solution
Speed tests look fine, ping seems a bit high though. Is the computer connected directly to the gateway or do you have a router in the middle? Did you contact Comcast? They may need to bounce your connection.