Internet connection speed problems?

my slow seed was my extension cable and the put up my mkz something on my router page im getting 18mbs now and thats on my old pc and using a wireless usb stick get back to bt there is a booster i heard about or change to talktalk i know they get a bad time but i dont have any problems with them now for 4years good luck and try dusting all the plugs and keep any sub woofers away from router or screens