Hello. I am going to upgrade my computer with 512 Memory instead of 256. I was going to buy this: http://www.bestbuy.com/site/olspage...goryId=cat01169&type=product&id=1077630669390PNY - 512 MB but then my dad said I could only get "Dell" Memory, because I have a Dell Dimension 4550 Desktop Computer. Is this true, or can I get that product at best buy and will it work?