I am not 100% sure of the differences myself. All I know is to use the upgrade version, you must have Win 98 or NT4(?) or newer Operating systems. it is cheaper, and as you ay is used as a carrot. I think it is so MS will sell more copies of the newer Operating system, especially to those that have older ones, as they make no money out of you once you already own a Operating system. As I have never used a upgrade OS, I can not say if it does camp with a licence number (serial number) for the install or not, but I would guess it must do really. I like many others would suggest that you install a fresh OS to a clean hard drive (no OS installed already). So if you own a Windows 9x CD, Inc ME, then the upgrade version of XP would be fine and cheaper for you. Hope i am not confusing anyone!! Trevnal ----- Original Message ----- > No a full version is not an upgrade, as you do not need to have either > another operating system installed first, or a blank hard drive and the > older operating systems CD and licence key handy. > > That is why upgrades are cheaper, as you are not buying the licence number > etc a fresh, even though the upgrade can be installed onto a empty hard > drive. > > A full version will over write the older version of Windows, or ask you if > you want to dual boot it, but you still need a full Licence number for that > new OS. Are you sure? The way I understand it is that the full version will install clean, or it will act as an update if you have anything installed from W98 onwards. The upgrade version can be installed clean or as an upgrade, but will only work if you have a valid serial number of another version of Windows (W98 onwards) . Don't follow what you mean on serial numbers..the upgrade version or the full version both have licence numbers. I assume the upgrade version is cheaper to act as a 'carrot' for those people who already own a previous version to upgrade to the new flavour Cheers Andy To unsub or change your email settings: //www.freelists.org/webpage/pctechtalk To access our Archives: http://groups.yahoo.com/group/PCTechTalk/messages/ //www.freelists.org/archives/pctechtalk/ For more info: //www.freelists.org/cgi-bin/list?list_id=pctechtalk