Hey guys... I just bought a MBP 15.4 (MC118LL/A) and I am going to run Fusion with XP... but I need some quick knowledge before I go and purchase XP from ebay. I noticed that people have some full versions of XP with the COA and without. Do I need one with a COA (Cert of Authenticity) in order to run XP properly using Fusion? Please let me know. This is my first Mac and am SO PUMPED for it!