Greetings: I install Windows 7 Home Premium family pack upgrade on one XP Pro sp3 desktop which has two HDDs, one EIDE (XP pro) and one SATA (Windows 7). After the installation, everything goes well and the machine boots perfectly. I activate Windows 7 with the provided key in the box. I then remove the EIDE HDD. The machine can no longer boot. If I reinstall Windows on the same PC but this time using only the SATA drive and reactivate Windows 7 will Window considers that I activate two machines? If so, how can I fix this dilemma? Note: I no longer wish to use the EIDE HDD. Any help would be greatly appreciated. Thanks.