I just bought a macbook pro which worked amazingly the first few days. But now it runs worse than my old computers. How can I fix this?

Question

I've barely had it for a week and its starting to run slow. Wepages take forever to load and its impossible top watch any videos online. I am connected wirelessly. My other much older laptop is working fine on this connection and for a few days my Macbook Pro was lightning fast. Now it runs slower than my 3 year old laptop. Also some videos tend to get choppy when I move the mouse. The audio, however, continues uninterrupted.  The laptop also started taking some time to shut down. I bought this open-box from Bestbuy. And right now Im realizing that this is actually a Macbook Pro Mid 2010 after looking up the specs which is strange as the box it was in says 2012.
Processor: 2.66 GHz Intel Core i7
Memory: 8 GB 1067 MHz DDR3
Graphics: Intel HD Graphics 288 MB
Software OS X Lion 10.7.3
Macbook HD: 731.83 GB free out of 749.3 GB.
Could the problem be that this is a 2010 laptop? I can still return it as its been a week.
I've cleared the cache, cookies, and history but it has little effect on the way videos and pages load.

Answer 1

Where did you buy this laptop?  I know if I opened a box expecing and having paid for a 2012 model and found a 2010 model, I'd be back at the store demanding an exchange quicker than you could imagine.  Open box or not, if you thought you were buying a 2012 model, you should get what you paid for.