Laptop so laggy, what to do?

I have had my laptop for a long time now and i play a lot of games on it, minecraft, Just cause, Gmod, etc. It didn't used to be so laggy but now it is running at like 10 fps. My friend says it is because i download so much things onto it but i don't think that that's the case. How can i make my laptop not so laggy, Like 30-40 fps?

Every time you download, you risk downloading a virus along with it. Every time you click on a link, same thing. Make sure you have good virus protection. You have probably picked up some bugs.