first off this isnt a riot problem this is a YOU problem
second what speeds are you paying for?
double check that to see if you're getting even that here
http://www.speedtest.net/
next are you using a wired connection? if no, expect slower speeds the farther away you are from the router. if you're only a couple feet away but still getting like 5 mbps when your paying for like 40+ that's not normal unless you have like 3 walls in the way.
to make sure there is no LAN internferance
open start
type cmd
type ipconfig
copy the default gateway
then type
ping -t "default gateway without the quotes"
check how long it takes for it to get the router
anything bigger then 20 or so is a problem 100+ is just straight impossible to work with, also check for loss packets ( they will show up as request timed out) if you getting an packet loss that shows there is an issue
if there is LAN interference i suggest getting a wired connection or switching to a 5ghz network ( LAN interference isn't as bad )
LASTLY
if you're on a wired connect ( or have tested the wired connection ) and you still getting less then 10-20 MBs of what you pay for , screen shot it and save it. your ISP will give you the excuse " speed will flux during high traffic hours blah blah blah", just take screen shots outside of 7 - 9 pm the farther apart they are the better. i do this typically for 2 days ( or 3 depending on if i have the time to call ). call your isp, demand a credit to you account for a technician to come out and swap the router. sometimes the router is the issue and i know I've had PLENTY of crap routers from Comcast.
if ALL of that fails then its an internal problem with your computer, dying adapters, which are super easy and cheap to swap out