I just bought my first Mac. I must load Windows onto the Mac to use my current expensive Adobe software and Quickbooks. I have a XP disk from my old computer but I would like to upgrade to Win7. My questions is: Can I load the XP disk and then buy the Win7 upgrade and load that? Or do I have to buy the full version of Win7 and load that and forget the XP disk altogether. The price difference between the upgrade and full version of Windows is $100.00+ so I would prefer to do the two disk step if it will work.