Welcome to Justanswer.com, my name is ***** ***** I will do my best to assist you.
Has your mac always been slow accessing the internet, through your sky router? Or did it only recently slow down?
To start with, I need to know the version of mac osx you have on your machine, you can check as follows.Click the apple sign at the top left of your screen, then click about this mac. And then where it says version, send that to me as a reply.