I'm running XP in a BootCamp partition on my iMac. I would like to upgrade the XP with Windows 7 when it is available. I have ordered the upgrade version. The Mac BootCamp doesn't let you use upgrade versions for Windows, because you have no way to verify that the earlier operating system was installed. But I'm wondering if I just tried to install Windows 7 upgrade over XP, if the installation program would recognize that I have XP and simply erase all the XP system and go ahead and install Windows 7. I don't care if I lose programs or the data. All that is backed up. Alternatively, is it possible to slipstream the information about previous XP registration into a Windows 7 installation disk, so it doesn't ask for verification during install?