We have a desktop computer that we had a licenced copy of Windows XP Pro installed on it. I ordered an upgrade copy of Windows 7 Ultimate for the desktop and Windows 7 (Full) Home edition for our laptop. On the desktop I correctly installed Windows 7 64 bit on a new computer disk, clean install, but the licence key I used was from the Win 7 Home edition as they had got mixed up. We were very keen to use it and have installed programs but now when I try to upgrade using the Ultimate licence key it tells me it is in the wrong format. Does anyone have any knowledge of how I can upgrade without losing any of the data and setup?