Let me clear up some activation questions for you all. You have to activate all versions of Windows Xp except the corporate version. All versions of home (oem, upgrade, retail, retail upgrade, etc.) as well as all versions of pro. You do not have to make a phone call, it does it over the internet. It does not send your name and information, just a "hash" of numbers that identifies your computer... They can not track you down from these numbers. If you reinstall it onto your computer that has already had it, you do not need to call Microsoft unless you have changed multiple components. It will go onto the internet to reactivate, and Microsoft will still have the "hash" it recognizes as your computer, so you will not have to call. The only time you have to call is if you change many (over 6 I think) components in a 90 day period. Every 90 days your code gets reset to allow for hardware upgrades. Hope that answers all questions.