Slow Internet but the laptop itself is fast?

My laptop (HP pavilion dv6) itself is actually very fast but when I use Internet explorer, the Internet barely loads. YouTube videos seldom play and it takes forever just to load a website. I've tried using ccleaner and it hardly did anything. I did the both the cleaner and registry. I have shaw Internet if that helps. My laptop is also connected to wifi via our linksys router. Our desktop Internet works perfectLy fine. Also, if it helps, we actually have a lot connected to the router. We have a wii, dsi, tfc Channel box, my itouch, and this laptop. Please help! Btw, I'm just a teen and the only one in my family who knows anything about technology but I can hardly understand much " tech speak"