What version of Windows came with the laptop?
How old is the laptop?
You say you think it is slow because of all the add ons over the years, but if you are on Windows 10 then that must be a new install (upgrade?) so the upgrade would have got rid of a quite a lot of the rubbish that has been collected over the years so I doubt that is the problem.
How large is your hard disk and is there plenty of room on it (a full hard disk can cause Windows to run slowly).
Is it your broadband that is slow and not your laptop? If you do laptop based activities (open a program for example) is that slow or only when you are on the internet?
Note you can do a Windows refresh or reinstall without having to install from a CD as all the Windows 10 code is hidden away on your hard disk..
See this web page, where it mentions "Refresh your PC" which reinstall Windows 10 but keeps all your programs and settings etc.
DONT do Reset Your PC or you will lose all your programs etc.
http://www.tenforums.com/tutorials/16397-repair-install-windows-10-place-upgrade.html