I currently have a licensed copy of Windows XP Pro and would like to upgrade to Windows 7 Ultimate. I am able to purchase an upgrade disc (Windows 7) from my university for less than $10. I understand that there is no direct upgrade path from Windows XP to Windows 7 so a "Custom" install is required. I have run the "Windows 7 upgrade advisor" and my system meets the requirements. I have backed up all of my data and located all of my program discs/installation files. Does any one know of a reason why I shouldn't use the upgrade disc as opposed to buying a full copy of Windows 7? I'm not trying to be cheap , but If I can can save a couple hundred bucks on the Operating System, then I can spend more money on hardware. Please advise.