Much more info required.
Cable or ADSL
What service are you on. Are you using a modem, a modem + a router, a Hub or a Superhub.
Is your problem just with wireless or generally.
If just with wireless what speed do you get wired and if using a modem + router what speed do you get when wired directly to the modem.
Enter 192.168.0.1 or 192.168.100.1 into your browser and post details of your signal levels. NB do not post your mac address.