How do I fix my internet connection?

[Phil]

wireless connection will always be slower that ethernet/cable connection

what speed are you paying for from comcast?
connect to router with a cable and one device only and go to speedtest.net (free sign up)
test your speed and compare to others in your area or isp or country
if poor speed talk to comcast - use speedtest (the same method as before 2 - 3 times a day for 1 week and use as evidence to comcast if they don't fix)
if speed is ok and it's your wifi consider checking your wifi router (upgrade if necessary) or look for powerline adapters (they use your existing electrical supply as network cable)