Test connection speed by using
Speedtest.net - The Global Broadband Speed Test do this when wired to the router, if speed is as expected then it is a wireless problem, try the same test on wireless, then try rebooting your router and your PC, if wireless is still slow try your machine on another wireless connection (next doors or a friends), if connection OK there, suspect router, otherwise suspect PC (see below), borrow a router from somewhere and try that, if at this stage you can determine that it is your router then you might want to call the broadband provider to check router and PC settings, before buying a new router, however some will charge as much as a new router just on phone call charges.
If it's your PC then there could be any number of reasons why it is slow, accidental damage to Ariel, wireless card, onboard chip, operating system etc etc, best to call an expert and ask for a fixed fee to fix it, or bin laptop and buy another.
As previous post, don't bother with buying software to clean your PC or speed things up, they are usually a waste of money.