New windows 8 Samsung Laptop is slower than 3 year old HP

I currently have an hp paviliondv4 (4gb RAM, 2.2GHZ with windows 7 and avast anti virus). I just bought and returned a Samsung NP550 (6GB RAM, 2.5GHZ with windows 8 and Kepersky security). As soon as I began surfing the net I noticed my new 600 dollar purchase was actually slower than my hp. I ran numerous speed tests and found out my less powerful hp was dogging my brand new more powerful computer. Best buy refunded the purchase completely but not with out a fight. At first they said it was not the computers fault and the Samsung was indeed faster as they pointed out the .3 GHZ advantage it had over the 2.2GHZ hp. They said internet speed is the only factor when speed testing...NONSENSE. I tested both computers on the same internet and the hp was faster in every category every time.The tech and I speed tested the two laptops once side by side and the hp won. Still he said It's not the computer. I told them to have a side by side race with my hp 50 times on the same internet opening a page and playing a video and that's when they refunded me completely including setup. I went to the back of the store and the display model was out performing my hp. Now I'm thoroughly confused. Maybe the display has a different security program? Is this a windows 8 issue? could Kapersky be causing lag? Did I get a defected model?
hp has AMD processor and the Samsung has core i5

It's between Kaspersky and Defective WiFi module.